Papers for

risk management teams

Papers whose findings have a practical use for this group, as judged from the abstract. Open a paper to read what it means in practice.

Large language model decision systems reduce wrong legal citations cost effectively

Commit or Abstain? System One Decision Models, LLMs, and Missing Legal Authority

Abstract: Given the enormous number of claims to be checked, verifiable legal AI requires scalable, cost-effective models that answer the practical needs of law. System One decision models are built on large language models but, instead of generating text, return a calibrated probability for each option. This suits the verification of legal authority, where the question is closed: a given holding, or none of them. We test whether such models abstain when the correct authority is missing. We extend CaseHOLD with an abstention condition in which the correct holding is replaced in 1,670 of 5,314 items, and compare four decision models with six generative LLMs. When no option is correct, generative LLMs still pick one in 38-86% of items; the most cautious decision model does so in 30%. On standard CaseHOLD, a decision model matches the best generative LLM (88.1% vs. 88.2%) at 1/55 of the cost. Accepting that LLM's answer only when a decision model agrees halves its wrong citations, and distilling a decision model's probabilities into Qwen3-8B, without labels, yields a well-calibrated local model. Legal AI should be judged by its wrong citations, not by accuracy alone.

Wed 21 OctArtificial IntelligenceComputation and LanguageComputers and Society
The gist
Checking legal claims automatically needs tools that can decide when they do or don’t find the right authority. The authors test models that don’t just guess answers but give probability scores, which helps them choose to abstain if no correct answer exists. They find decision models are more cautious and cheaper than typical language models, cutting wrong legal references in half when combined. This approach could make legal AI more reliable by focusing on reducing incorrect citations, not just overall accuracy.
Open → 2610.29961v1

Quantile methods improve accuracy bounds in reinforcement learning returns

Near Minimax Rate for Quantile Distributional Reinforcement Learning

Abstract: In this paper, we study quantile distributional policy evaluation, where the return distribution under a given policy is approximated by the quantile Bellman fixed point $\bmη_m$. We investigate the statistical accuracy of estimating $\bmη_m$ across quantile resolutions under Wasserstein distances. Assuming access to a generative model, we construct a quantile fixed point estimator $\bmη_m^{(n)}$ from an empirical Markov decision process and establish non-asymptotic error bounds under Wasserstein distances. When reward densities are uniformly bounded away from zero, we obtain a root-$n$ high-probability bound simultaneously over all resolutions $m$ and all Wasserstein orders $1\le p\le\infty$. When reward densities vanish at the support endpoints, we show that continuity and endpoint monotonicity suffice to preserve the same resolution-independent rate for $1\le p\le2$. For $p>2$, we establish a root-$n$ bound with coefficient $m^{1/2-1/p}$, together with a slower, resolution-independent $n^{-1/p}$ bound for every finite $p>2$. We further obtain resolution-independent $W_\infty$ consistency governed by the continuity modulus of reward quantile functions. To investigate the sharpness of these bounds, we characterize the exact local asymptotic minimax risk at each fixed resolution as the expected Wasserstein-coordinate norm of the efficient Gaussian limit and prove that our estimator attains it. We then examine the resolution dependence of this optimal local risk. A regular one-state instance has resolution-independent local risk constants, whereas a single endpoint-vanishing two-state instance exhibits growth of order $m^{1/2-1/p}$, up to logarithmic factors along a resolution subsequence, for every $p>2$.

Wed 21 OctMachine Learning
The gist
This paper studies a way to better estimate the full range of possible future outcomes in decision-making tasks by focusing on quantiles, which are points that split data into equal parts. The authors look at how accurately these quantiles can be estimated in different settings, providing mathematical guarantees on the error. They also explore how these error bounds depend on factors like the number of quantile points used and certain properties of the reward distribution. Their analysis shows when their approach reaches the best possible accuracy and how challenging cases affect this.
Open → 2610.29595v1

CrashGym shows experiments help market crash choices by 57 percent

CrashGym: Measuring the Decision Value of Experimentation for LLM Agents in Counterfactual Market Crashes

Abstract: Language-model agents are increasingly asked to run experiments, yet benchmarks rarely measure whether those experiments improve the decisions they are meant to inform. We introduce CrashGym, a deterministic, replayable limit-order-book simulator in which an agent must choose between a deleveraging intervention and a liquidity backstop for a market about to suffer a shock-triggered crash. Before committing, the agent may query intervention experiments in a laboratory realization of the market. Its choice is then scored on an independently seeded target realization in which the simulator executes every feasible intervention, so regret relative to the best intervention is computed by directly simulating every alternative on the same target repeats, with no human or model-based judging. The simulator implements each amplification channel---persistent price impact, liquidity withdrawal, margin-driven liquidation, and an evolving strategy mix---as an explicit mechanism that can be switched on in stages. In a prospectively specified study on 24 newly sampled worlds, laboratory access reduces the mean regret of the one deployment with a complete record (Luna) from 8.878 to 3.785, a paired reduction of 5.092 utility units (nominal 95% world-bootstrap interval: 1.028--9.507), or 57.4% of the OBSERVE-ONLY mean. Prospective comparisons for two further deployments are incomplete; in a separate exploratory study, mean regret is lower with laboratory access for all four deployments evaluated. A laboratory whose strategy mix evolves endogenously yields no established advantage over one with a fixed mix. CrashGym thus measures the value of experimentation as avoided decision loss and lets simulator detail be judged by the decisions it supports.

Wed 21 OctArtificial Intelligence
The gist
When financial markets face sudden crashes, it’s hard for agents to decide how best to intervene. The authors built CrashGym, a simulator where agents can try out different market interventions before choosing one. They show that having a chance to experiment reduces the mistake of picking a bad intervention by over half. This helps measure how much experimenting improves decisions in market crises.
Open → 2610.29245v1

Data-driven approach discovers extreme scenarios without geometry limits

Geometry-Agnostic Data-Driven Discovery of Extreme Scenarios

Abstract: We introduce a two-stage data-driven neural framework for discovering dynamically admissible extreme scenarios. Rather than assuming prior knowledge of the governing equations, the first stage infers the effective dynamical constraints directly from observational data. When the underlying physical system possesses suitable symmetries, the learned dynamics can be represented in a geometry-agnostic form, independent of any fixed grid, coordinate system, dimensionality, and intrinsic curvature. In the second stage, a physics-informed neural-search uses this learned dynamics to uncover rare, high-impact coherent structures that may not have appeared in the original observations. We demonstrate this framework through representative examples of increasing dimensionality and geometric complexity. Starting from a traditionally learned Duffing dynamics, we find a homoclinic pulse as a plausible localized extreme scenario. Next, since the same equation also appears in the stationary nonlinear Schrodinger system, with the coordinate interpreted as space instead of time, this pulse becomes a standing soliton. We then retrain the first stage using a geometry-agnostic neural representation, enabling the learned dynamics to be lifted to higher-dimensional space to obtain higher-dimensional solitary profile, known as Townes soliton. Finally, with a Liouville system, we demonstrate that dynamics learned from data on a (1+1)-dimensional Lorentzian quasi-manifold can be transferred to a (2+0)-dimensional Euclidean manifold to identify an instanton. Our approach can be applied to other coherent spatiotemporal structures, including kinks, rogue waves, compactons, peakons, and potentially even singularities, with applications in risk analysis, nonlinear forecasting, and anomaly detection.

Tue 20 OctMachine Learning
The gist
Sometimes unusual yet important events in physical systems are hard to predict because their rules are unclear or complex. This paper introduces a two-step AI method that first learns how a system behaves directly from data, without needing to know its detailed rules or geometry. Then, it uses this learned understanding to find rare and impactful patterns that didn't appear in the original data. This method works for systems of different shapes and dimensions and can help identify extreme events in physics and other fields.
Open → 2610.28487v1

Polyscene automates scenario planning by generating diverse future narratives

Polyscene: Scenario Planning as Diversity Planning

Abstract: Scenario planning is a foresight practice in which analysts construct a small set of plausible futures and prepare an organisation for each. Each scenario is a narrative that must be plausible, internally consistent, relevant and challenging, and the set as a whole must be differentiated. The practice remains manual: a workshop (i.e., a facilitated meeting in which a small group of experts writes the narratives) considers only the factors it has time for, carries the biases of the experts who run it, and cannot be redone whenever conditions change. In this paper, we automate scenario planning by casting it as a diversity planning problem, in which two scenarios differ when they end in different narratives on the analyst's drivers. The result is a set of scenarios, one for each narrative that the topic can reach within a budget. Our implementation, Polyscene, is a generic engine that generates scenarios from a topic. We use geopolitical conflicts and shipping-route disruptions as case studies. For the first, we build the planning problem's initial state from the GDELT Project so it reflects current relationships among the countries involved. Polyscene then generates scenarios showing how relationships among those countries change. With a board of six countries as of 1 January 2021 and a budget of five events, the conflict set puts five of the 15 country pairs at war, and each of the three wars that break out among these countries by 1 January 2026 ends a scenario. For the second, we build the initial state from ship traffic, a supply-pressure index, and the news, and Polyscene generates scenarios showing what a closed or diverted route could do to a manufacturer's parts stock. With four routes per board and the same date and budget, each set includes three outcomes, and the Suez Canal set includes the March 2021 blockage and the December 2023 Red Sea container diversion.

Tue 20 OctArtificial Intelligence
The gist
Planning for future uncertainties usually means experts manually write a few possible stories about what might happen. The authors present Polyscene, a tool that automatically creates many different future scenarios by imagining various events unfolding within given limits. It uses real-world data like geopolitical news and shipping information to start these stories realistically. This helps organizations explore a wider range of possible futures without the usual biases and time limits.
Open → 2610.28102v1

AlphaBet improves event forecasts by learning to find evidence early

AlphaBet: Reinforcement Learning for LLM Event Forecasting Agents

Abstract: Forecasting an unresolved event requires finding relevant evidence and deciding how strongly it supports each outcome. Yet outcome-based training of Large Language Model (LLM) forecasters often begins with preassembled evidence at a single prediction date, leaving evidence acquisition outside the learning loop. We introduce AlphaBet, an agentic reinforcement learning (RL) framework that trains a single LLM policy to search, reason, and report probabilities across multiple pre-resolution dates. Each dated forecast is scored by a proper scoring rule against the eventual outcome, allowing one resolved event to supervise decisions under different information states. We decompose forecasting regret into an evidence-acquisition gap and a probability-reporting gap, and show that Group Relative Policy Optimization (GRPO)'s standard-deviation normalization can distort the reporting target under multi-class proper scores. On GLM-4.5-Air, AlphaBet reduces the Brier score from 0.731 to 0.626 on Forecast-Dojo and from 0.612 to 0.528 on FutureX. Controlled ablations attribute these gains to multi-date training and show that they come from improvements in both information acquisition and probability reporting. Our empirical results validate that GRPO's std normalization degrades proper-scoring-rule performance while leaving top-outcome accuracy largely unchanged.

Thu 15 OctMachine LearningArtificial Intelligence
The gist
When predicting events that haven’t happened yet, it’s important to not only guess outcomes but also to find the information that supports those guesses. The authors show that current methods often miss training the model to gather evidence properly. They created AlphaBet, a system that trains a language model to search for relevant information and make better predictions over time. Their work helps improve both how evidence is found and how probabilities are reported, leading to more accurate forecasts.
Open → 2610.22684v1

Time partitioning model finds persistent patterns in financial time series

Time-partitioning Gaussian Process Mixture Model

Abstract: We propose the Time-partitioning Gaussian Process Mixture Model (TPGPMM), a Bayesian nonparametric framework for identifying persistent regimes and modelling nonstationary dependence in time series. The model combines an adaptive Pitman--Yor prior on contiguous segmentations with regime-specific Gaussian processes, without imposing Markovian within-regime dependence. Learning the Pitman--Yor discount parameter allows adaptation to homogeneous and heterogeneous regime lengths. A split--merge Metropolis-within-Gibbs sampler with exact Gibbs boundary updates jointly learns change points and model hyperparameters, quantifying uncertainty over segmentations and within-regime dynamics. With an RBF kernel and a fixed, conservative observation-noise level, TPGPMM favours sparse segmentations that distinguish persistent shifts from transient shocks. Simulations demonstrate recovery of the regime structure. Applications to the CBOE Volatility Index (VIX) and the 10-year United States Treasury yield identify regimes aligned with major market and monetary-policy events. Variants that estimate observation noise improve predictive accuracy relative to the main specification, but can produce less sparse or less event-aligned segmentations. A variant with regime-specific means fits better than a fitted stationary Gaussian process and forecasts about as accurately. These results highlight a trade-off between interpretable regime identification and predictive accuracy.

Wed 14 OctMachine Learning
The gist
This paper presents a new statistical model to identify lasting patterns and changes in time-based data, like stock market numbers, without assuming simple dependencies within each pattern. The authors developed a method that adapts to different lengths of time periods and can measure uncertainty about when changes happen. Their model helped spot changes in financial indices that coincide with major events in markets and policy. They also found that adjusting certain settings can improve prediction accuracy, but might reduce how clearly the model identifies meaningful patterns.
Open → 2610.20860v1

Structured neural solvers improve pricing accuracy for complex financial models

Beyond Time Induction: Structured Conditional Neural Solvers for Parametric Stochastic-Volatility Pricing

Abstract: Physics-informed neural networks provide a flexible framework for learning parametric PDE solution families without labeled data, yet preserving accurate derivatives across heterogeneous regimes remains challenging. Structured neural solvers offer compact representations, but restrictive conditional parameterizations can limit adaptation across the solution family. We introduce BeTINN, a structured conditional architecture extending time-induced modulation through multi-directional time-parameter conditioning and a joint residual pathway. We evaluate BeTINN on the Heston stochastic-volatility PDE, a demanding parametric problem with mixed derivatives and economically relevant first- and second-order sensitivities. BeTINN improves joint accuracy across normalized option value and key sensitivity metrics relative to our baselines. Controlled ablations characterize the roles of its architectural components. We further find that validation physics loss is informative but does not fully determine differential fidelity, and that accurate solution values can coexist with localized derivative errors. These results support structured conditional adaptation and motivate derivative-aware evaluation when sensitivities are downstream quantities of interest.

Tue 13 OctMachine LearningComputational Engineering, Finance, and Science
The gist
Pricing financial options accurately involves solving complex mathematical equations that describe how prices change over time with uncertainty. The authors developed a new kind of neural network, called BeTINN, which better captures how these equations behave across many different scenarios. Their method improves accuracy not only in predicting option prices but also in important related quantities that traders use to manage risk. They also found that checking just the overall prediction quality isn't enough; you need to look carefully at how well the network predicts detailed changes too. This work helps make advanced financial modeling faster and more reliable.
Open → 2610.19254v1

Bayesian optimization improves risk-based decisions with uncertain models

Bayesian Optimization of CVaR with Unknown Hyperparameters

Abstract: We study Bayesian optimization of the Conditional Value-at-Risk (CVaR) of an expensive black-box function that depends on a decision and an environmental variable. Existing no-regret algorithms assume that the correct Gaussian process (GP) kernel and its hyperparameters are known. In practice, however, they must be estimated from limited data, often yielding a misspecified surrogate. This is especially damaging for CVaR because misspecification can distort the estimated tail-risk and thus lead to catastrophic decisions. We propose HE-CV-UCB, the first no-regret algorithm for CVaR Bayesian optimization with unknown GP hyperparameters. Given a finite candidate set containing a well-specified model, HE-CV-UCB adaptively eliminates those inconsistent with the observed data, actively queries where the survivors disagree, and returns a design that is robust across the surviving candidates. We prove that it attains cumulative regret matching the oracle rate of CV-UCB up to a factor depending only on the candidate set's size. Across synthetic benchmarks and three real-world applications, HE-CV-UCB achieves competitive performance and frequently outperforms existing CVaR Bayesian optimization methods.

Tue 13 OctMachine Learning
The gist
Sometimes, when trying to make expensive decisions in uncertain environments, we want to avoid rare but bad outcomes. Conditional Value-at-Risk (CVaR) is a way to focus on these worst-case possibilities. The authors address the problem that existing methods assume we know everything about the model’s details, which we usually don’t, causing errors in risk estimates. They propose a new method called HE-CV-UCB that can work well even when the model’s details are unknown by intelligently testing and narrowing down possible models. Their method reliably finds decisions that minimize bad outcomes and works well in both tests and practical problems.
Open → 2610.18306v1

Polymarket weather forecasts bias shifts from longshots to favorites over time

Time-Varying Favorite-Longshot Bias in Polymarket Weather Markets

Abstract: Prediction-market prices combine traders' judgments about future outcomes, but their errors may be concentrated in particular price ranges and change as settlement approaches. Prior cross-category evidence shows that Polymarket weather markets have larger pricing bias than other major categories, without separating low-price longshots from high-price favorites. This study compares the two ranges at different horizons in daily maximum-temperature markets. Event-level probability scores, cubic B-spline recalibration, and Buy-NO tests are used to examine the form and effect of the bias. Longshot overpricing mainly occurs at distant horizons, whereas favorite overpricing becomes much stronger during the final 1-12 hours and is nearly one order of magnitude larger. Event-level scores improve toward the daily temperature peak, while simple recalibration yields no statistically significant gains. The Buy-NO results in the corresponding time windows also show that the main pricing error is concentrated at the favorite end.

Fri 9 OctDatabases
The gist
Prediction markets where people bet on weather outcomes sometimes misprice probabilities. This study finds that bets on unlikely weather events are priced too high far in advance, but as the weather event gets closer, bets on more likely outcomes become overpriced instead. The biggest bias happens just hours before the event, especially for favorites. Attempts to correct these biases using simple methods weren't clearly effective. The authors use special scoring and tests to analyze these changing biases over time.
Open → 2610.13593v1

Monte carlo tree search improves sparse feature selection for financial regression

$L_0$ Feature Selection via Monte Carlo Tree Search in High-Dimensional Financial Regression

Abstract: Feature selection is a central problem in high-dimensional financial regression, where large numbers of engineered variables and strong correlations among predictors reduce model stability and interpretability. $L_1$ regularization (Lasso) is widely used for sparse regression, but its shrinkage can be restrictive when informative signals are spread across correlated variables. Exact sparse regression avoids this shrinkage but requires solving a combinatorial optimization problem that is computationally difficult and is typically fit to minimize in-sample rather than out-of-sample error. This paper presents a feature selection framework based on Monte Carlo Tree Search with Generalized Nested Rollout Policy Adaptation (GNRPA). Feature selection is formulated as a sequential decision process, and candidate subsets are scored by their out-of-sample validation performance rather than training error. The method also supports a lexicographic objective accounting for subset size and multicollinearity. We study this approach on a contemporaneous explanatory regression task: explaining the weekly return of the NASDAQ-100 index from 1,072 engineered features spanning market, macroeconomic, and factor data. This isolates the value of subset selection under multicollinearity from the separate problem of predictive forecasting. On this task, the proposed method identifies sparse feature subsets with higher out-of-sample explanatory power than an optimized Lasso baseline, reaching an out-of-sample $R^2$ of 0.6961 versus 0.6313 for Lasso. These results suggest that Monte Carlo Tree Search is a practical alternative to convex regularization for sparse explanatory feature selection in financial regression, with potential value for factor attribution and risk decomposition where transparency matters as much as out-of-sample fit.

Fri 9 OctMachine Learning
The gist
Picking the right key variables is important when making sense of lots of financial data, but usual methods struggle with variables that are closely related. The authors use a method called Monte Carlo Tree Search to try out different groups of features, focusing on how well they explain new data instead of just fitting old data. This approach found smaller sets of variables that better explained stock index movements than a popular technique called Lasso. Their approach offers a new way to pick important features with better clarity and accuracy in financial studies.
Open → 2610.13574v1

Typedbench measures reliability and risks in decision AI probabilities

TypedBench: A Benchmark for Calibration, Framing Sensitivity, and Cost in System One Decision Models

Abstract: System One models output calibrated probabilities over typed answers such as categorical choices, ordinal levels, or binary outcomes, via a non-generative interface. Software can act on these probabilities through thresholds, cost-weighted choices, and escalation rules. Consequently, if these probabilities are miscalibrated or wording-sensitive, the software ma take unintended actions leaving human operators with no textual rationale to inspect. Current evaluations largely report accuracy and calibration on public classification datasets without a clear reference. We present TypedBench, a benchmark for typed decision models like Jev built from seven policy-labelled generators and nine evaluation suites. We report accuracy as median and range across paraphrases, and calibration error relative to the finite-sample noise floor of a matched, perfectly calibrated predictor. We assess probability quality through selective prediction, ordinal proper scoring rules, and realised cost under asymmetric cost matrices. We evaluate a hosted model, an open encoder, and a family of open decoders spanning 0.8B-9B parameters on identical items. The hosted model follows the stated policy but is wording-sensitive and systematically underconfident; under asymmetric costs, using its probabilities can be worse than taking its top answer. Decoders route exactly and are slow as options or questions are added. The decoder is least accurate on policy questions and degrades with more options. Overall, typed decision models must be evaluated jointly on policy adherence, wording robustness, probability quality, and induced decision outcomes.

Thu 8 OctArtificial Intelligence
The gist
Some AI systems give answers with probabilities, helping software decide what to do next. The authors found that these probabilities can be wrong or sensitive to small changes in wording, which can cause software to make bad decisions without clear explanations. They created TypedBench, a test set to check how well these systems perform on tasks where decisions matter, especially when costs of mistakes differ. Their tests showed current models often have problems like being too uncertain or slowing down with more options. The paper suggests evaluating such models not just by accuracy but also by how well their probabilities match reality and how stable their decisions are.
Open → 2610.11392v1

Data visualization promotes healthy skepticism towards AI models

Healthy skepticism in AI: a data visualization research agenda

Abstract: Research in data visualization of artificial intelligence (AI) models has historically focused on enhancing trust through visual explanations of AI. The trustworthiness line of work was built at least partially on an assumption that humans were critical users unlikely to adopt AI technology. It is increasingly clear that human trust levels in AI span, in fact, a wide range from critical to over-reliant. There is an urgent need to support both trust and healthy skepticism in AI solutions. We argue that it is healthy for humans to adopt a skeptical view both on the results of AI models and on the use of such AI models. We share our thoughts on the rising phenomenon of over-reliance on AI models, the risks and opportunities in using AI models, and the role of data visualization in over-reliance situations where humans are not motivated to engage in critical thinking.

Wed 7 OctHuman-Computer InteractionArtificial Intelligence
The gist
People tend to either trust or rely too much on AI systems without questioning them. The authors point out that it's important for humans to stay skeptical about AI's results and usage. They discuss how visualization can help people see risks and avoid blindly trusting AI outputs. Their paper suggests a direction for creating AI tools that encourage critical thinking without overwhelming users.
Open → 2610.09740v1

Learned monotone risk scoring matches hand-crafted summaries well

Measuring Learned Monotone Temporal Aggregation at Matched Admissibility

Abstract: Risk regulation imposes directional constraints on scores; we adopt their strict per-input form -- the score monotone non-decreasing in every exposure input -- as a normative commitment. Deployed pipelines -- monotone hand-crafted aggregates feeding sign-constrained gradient boosting -- already satisfy it by composition, so constrained-versus-unconstrained comparisons price a guarantee the incumbent has for free. We instead hold admissibility fixed on both sides and measure what learning the aggregation is worth. Our instrument is a recurrent network whose state is classical risk statistics (an exponentially weighted moving average and a high-water mark with learned transforms), monotone by construction in every input and per MC-dropout sample. The central finding, by functional regression, is a subsumption boundary: a learned monotone channel reproduces the geometrically weighted separable family of hand-crafted statistics, one channel per member, to Spearman $ρ\ge 0.996$, approximates window statistics with measurable ceilings, and fails at consecutivity ($ρ= 0.924$) and time localization (0.628), both structural, and at the exposure floor (0.829), a learnability boundary. One explicit admissible basis repairs each failure (rank correlation 1.000). In or near the separable family, learned and engineered aggregation are substitutes, and the learned channel is never statistically behind at full sample size and specified capacity. Its advantages are incumbent-specific: a committed grid pays up to 0.019 AUC in decay regions it leaves uncovered (the learned channel stays within 0.004 of the strongest engineered consumer at every swept point); the highest-dimensional comparator degrades fastest with scarce data; and beyond the training support, grid-fed tree-ensemble scores go flat while a strictly increasing head keeps ranking. No single incumbent is dominated on all three axes.

Sun 4 OctMachine Learning
The gist
This paper deals with scoring risk exposures in a way that ensures the score never decreases when exposures grow. The authors compare traditional hand-crafted scoring methods with a learned recurrent neural network designed to always produce increasing scores when any input exposure increases. They find that the learned method very closely matches classical, engineered risk statistics and can approximate them effectively, but some specific types of temporal aggregation are harder to learn. Adding specialized components to the learned method can fix these issues. The paper shows the learned approach never falls behind the hand-crafted one in accuracy when enough data is available and can handle data patterns outside its training better.
Open → 2610.05196v1

Optimal strategy found for five expert prediction game in finite time

The finite-horizon five-expert prediction problem

Abstract: We give an explicit solution to the five expert prediction with expert advice partial differential equation (PDE) in the finite-time horizon setting. The solution formula establishes that the adversary's rank strategy $(1,0,1,0,0)$ is globally optimal, and the COMB strategy $(1,0,1,0,1)$ is optimal exactly on the set where $x_1=x_2$ and $x_3=x_4$. The formula is derived from the solution of the geometric-stopping problem given in our companion paper through the transform principle of Bayraktar, Ekren and Zhang, which links the two problems by a Laplace transform. Inverting the transform term by term expresses the solution through a series of Gaussian and complementary error function kernels. The optimality of $(1,0,1,0,0)$ is reduced to the signs of $41$ one-variable Gaussian series, which are certified with computer assistance by Poisson summation, first-mode domination and interval arithmetic on $1616$ rational cells. The proofs of our main theorems, certificates included, are also formalized in the Lean proof assistant.

Tue 29 SeptComputer Science and Game TheoryMachine Learning
The gist
This paper solves a puzzle in decision making where you have five experts giving advice over a limited time. The authors found the best way for an opponent to act to make predictions hardest to get right. They used advanced math tools and computer checks to prove their solution. This work links two complex problems and provides exact formulas to guide decisions.
Open → 2609.38035v1

Financial models improve by tracking volatility clustering patterns

Volatility-Clustering Adaptation for Financial Time Series

Abstract: Time-series foundation models are increasingly adapted to new domains through fine-tuning on target data, under the implicit assumption that more target data yields better forecasts. We show that this assumption can fail in financial forecasting, where individual price changes are difficult to predict, but large moves tend to cluster, creating alternating calm and turbulent periods. Using financial foundation models trained on price bars of open, high, low, close, and volume, we argue that adapting to financial domains requires training signals beyond next-token prediction. We introduce Volatility-Clustering Adaptation (VCA), which augments next-token cross-entropy with a differentiable penalty on the autocorrelation of squared returns, the standard statistical signature of volatility clustering. This additional objective provides a multi-step training signal by matching the resulting dependence structure of autoregressive rollouts to those of the realized future. Across three asset sets and two evaluation conventions, VCA improves adaptation over the pre-trained model, with the strongest gains under the primary evaluation (\textsc{fore}), driven primarily by reduced variance error. Overall, our results suggest that effective financial adaptation requires objectives that capture domain-specific temporal structure beyond token-level prediction.

Tue 29 SeptMachine Learning
The gist
Predicting exact price changes in finance is tough, but big price swings tend to happen in groups, making calm and busy periods. The authors show that simply training models to guess the next price isn’t enough for good forecasts. They propose a new technique called Volatility-Clustering Adaptation that teaches models to pay attention to these clusters of big changes. Their method helps models better match the real patterns of market ups and downs, improving forecasting accuracy especially by reducing unpredictable errors.
Open → 2609.37715v1

Chain improves event forecasting calibration with causal temporal modeling

CHAIN: Calibrated LLM Forecasting via Causal-Temporal Hypergraph Inference

Abstract: Large language models have achieved significant progress in event forecasting, yet their probability outputs exhibit systematic calibration bias that varies heterogeneously across different domains and question types, undermining the trustworthiness of probabilistic outputs for decision-making under uncertainty. However, existing calibration methods typically correct probability outputs after prediction is complete, without modeling the structural sources of bias within the prediction process itself. To address this challenge, we decompose probabilistic prediction over causal-temporal hypergraphs into three stages, evidence weighting, evidence aggregation, and source fusion, and propose CHAIN, which designs stage-specific mechanisms to mitigate bias at each stage: (i) modulating the temporal decay function by causal topological distance, (ii) aggregating approximately independent causal chains via Noisy-OR after direction-aware deduplication, and (iii) driving adaptive fusion by causal coverage and directional balance. Experimental results on cross-domain forecasting benchmarks show CHAIN outperforms existing methods in expected calibration error, Brier score, and accuracy. Our project is available at https://github.com/QwenQKing/Chain.

Tue 29 SeptMachine LearningComputation and Language
The gist
Predicting future events with large language models is helpful but often not very accurate in showing how confident the models are. The authors identify that this issue comes from hidden patterns in how the predictions are made over time and cause-effect relationships. They create a new method called CHAIN that breaks down the problem into steps and improves confidence scores by carefully weighting, combining, and balancing information based on cause and time. Tests show CHAIN makes better and more trustworthy forecasts across different topics.
Open → 2609.36689v1

Entropy-Shapley method reveals how features drive multivariate uncertainty

A Hierarchy of Entropy-Shapley Games for Multivariate Predictive Uncertainty

Abstract: Modern probabilistic machine learning models increasingly produce multivariate outputs with complex dependence structure, from multi-step time-series forecasts to sample path predictions. Understanding which input features drive the predictive uncertainty is important for risk-aware decisions, model diagnostics, and deciding whether the uncertainty should be mitigated or hedged against. This attribution problem requires a choice of how dependencies between output components are treated. Existing approaches reduce the output to a scalar through aggregation or projection before attribution, thereby obscuring whether features affect marginal uncertainty, dependence structure, or both, while component-wise analyses can miss dependence effects entirely. We close this gap by introducing a hierarchy of three entropy-based Shapley games that make this output-side choice explicit for any ordered multivariate outcome, ranging from per-component marginal entropy to fully joint entropy. The hierarchy isolates a cross-component attribution term that captures how each feature shifts the dependence between output components, a quantity invisible to component-wise methods. We establish a chain-rule decomposition of the joint attribution and characterize the cross-component term through conditional total correlation, providing both closed-form and sample-based estimators. Finally, we demonstrate how the framework captures differences in learned joint structure across probabilistic models from distributional regression to a zero-shot time series foundation model.

Mon 28 SeptMachine Learning
The gist
Predictive models often guess multiple related outcomes at once, and understanding which inputs cause uncertainty in these guesses is tricky because the outputs influence each other. The authors introduce a new way to measure how each input feature affects both the individual uncertainties and the connections between outputs, using a special kind of game based on entropy. Their method can tell if an input mostly changes an output’s own uncertainty or how different outputs relate to each other. This helps improve decisions and model understanding where knowing uncertainty matters.
Open → 2609.35217v1

Kit generates multiple future financial candlestick paths accurately

KiT: A Foundation Model for Financial Time-Series Forecasting using DiffusionTransformers

Abstract: Financial candlestick forecasting is fundamental to quantitative investment, yet it remains exceptionally challenging due to extremely low signal-to-noise ratios and vast heterogeneity across markets and instruments. Existing approaches have largely attempted to introduce deep learning to capture hidden temporal features, but most adopt an auto-regressive formulation, which leads to error accumulation during inference. Meanwhile, general-purpose time-series foundation models are not tailored to the unique structure of k-line data and yield unsatisfactory performance on downstream candlestick forecasting tasks. To tackle these problems, we introduce KiT, a K-line Diffusion Transformer foundation model, and reformulate future prediction as conditional path generation via flow matching: given a historical context window, the model generates an ensemble of plausible future OHLCV trajectories. We pre-train KiT at multiple parameter scales on billions of candlestick bars spanning multiple markets and timescales. Across three markets and seven resolutions, KiT attains a mean return RankIC of 0.057 and a mean volatility RankIC of 0.66, leading at every timescale and outperforming both task-specific financial forecasters and general time-series foundation models. Code will be available at: https://github.com/Luciferbobo/KiT.

Mon 28 SeptMachine LearningComputer Vision and Pattern Recognition
The gist
Predicting future prices in financial markets is very hard because the data is noisy and varies a lot across different markets. The researchers created a new model called KiT that looks at the history of price data and generates several possible future scenarios instead of just one prediction. KiT was trained on a huge amount of data across many markets and time lengths, making it stronger and more general than earlier models. It performs better at forecasting than both specialized financial models and general time-series models.
Open → 2609.34507v1

Probability estimates from large language models do not reliably improve over base rates

Can LLMs Predict the Future? A Brier Score Analysis of Prediction Markets

Abstract: We study whether model upgrades improve probability estimates for prediction-market questions. Our Resolved Market Forecasting (RMF) benchmark contains 3,000 resolved binary questions across nine domains, on which we evaluate six Claude and Qwen model variants using a question-only, zero-shot protocol. We assess Brier scores relative to an empirical base-rate predictor, examine their Murphy decomposition, and compare models through paired differences, with results stratified by event category and timing relative to training cutoffs. In the reported post-cutoff stratum, the four Claude models achieve Brier scores of 0.183-0.192, improving on the base-rate reference by 0.024-0.033. Qwen 32B does not significantly outperform that reference, although its paired Brier is 0.024 lower than that of the 7B checkpoint. The evaluated Claude version and tier upgrades yield no significant improvement. Within-model differences across event categories exceed the observed differences among Claude variants. These results show why forecasting scores should be interpreted alongside simple probability baselines and question composition: under this protocol, newer versions or higher model tiers do not consistently produce more accurate probabilities.

Sat 26 SeptArtificial Intelligence
The gist
This paper checks if newer large language models (LLMs) better predict chances of real-world events in prediction markets. The researchers found that upgrades in LLMs didn’t consistently give more accurate probability predictions compared to a simple baseline that uses average past outcomes. They tested models on thousands of questions across various topics and measured their accuracy using a scoring method called the Brier score. The results suggest that just making language models bigger or newer doesn’t guarantee better forecasts of future events.
Open → 2609.32885v1

Multivariate prediction sets improve by focusing on residual tails

Tail-Aware Geometry Learning for Conformal Ellipsoids

Abstract: This paper studies multivariate conformal prediction (CP), a distribution-free uncertainty quantification framework with finite-sample coverage guarantees. The efficiency of multivariate prediction sets hinges critically on the residual geometry encoded by the nonconformity score, while existing minimum-volume methods rely on quantile thresholds that ignore tail residual severity and implicitly bind geometry learning to coverage level. We propose a tail-aware geometry learning framework for conformal ellipsoids that decouples tail sensitivity in geometry learning from the final coverage guarantee. Using a two-split design, we learn the metric matrix via volume minimization under a CVaR constraint on an estimation split, then apply standard conformal calibration on a held-out calibration split. The resulting problem is convex and admits a bounded-reweighting interpretation that prioritizes high-residual samples. Moreover, we theoretically characterize the trade-off between ellipsoidal volume and tail severity. Experimental results demonstrate the effectiveness of the proposed method.

Wed 23 SeptMachine Learning
The gist
Making reliable predictions about many things at once is hard, especially when you want to quantify uncertainty without assumptions. The authors studied how shapes used for predictions can better handle extreme, unusual errors by learning from the severity of those errors instead of just their frequency. They show a way to create prediction sets shaped like ellipsoids that prioritize bigger errors when shaping their size and form while still guaranteeing how often they cover true results. Their experiments suggest this new method works better than older ways that ignore extreme errors' severity.
Open → 2609.27221v1

Falling trees improve risk sorting with clear decision paths

Falling Trees: A Model Class for Interpretable Risk Prioritization

Abstract: Many real-world decisions require prioritizing high-risk cases, such as clinicians prioritizing high-risk patients before lower-risk ones. Falling rule lists (FRLs), which are ordered if--then rules with monotonically decreasing risks, provide an interpretable framework for such tasks; however, their single-path structure yields a highly restricted model class. We introduce falling trees, a new family of interpretable models that enforces the same monotonic risk constraint while permitting tree-structured branching. We present GRAVITree, a novel dynamic-programming-with-bounds algorithm for learning the Rashomon set of falling trees under depth and branching constraints. Our formulation can interpolate between rule lists and full decision trees, enabling user-desired model expressivity. In a new clinical dataset and in many public classification benchmarks, falling trees match or outperform FRLs and other interpretable baselines, often producing more sparse decisions for high-risk instances. Our results show that falling trees strike a practical balance between interpretability, expressiveness, and risk prioritization for high-stakes settings.

Sun 20 SeptMachine Learning
The gist
Many situations require sorting things or people by risk, like doctors figuring out which patients need urgent care. Previous methods used simple lists of rules that always reduced risk as you moved down the list, but these were limited because they only followed one path. This paper introduces "falling trees," which keep the risk always going down but allow branching decisions like a tree, making models more flexible and just as easy to understand. The authors developed a new method to find the best such trees and showed they often work better than older methods, especially in medical data. Falling trees balance being easy to understand with being powerful enough to catch important risk patterns.
Open → 2609.23780v1

Language model competence improves event forecast accuracy selectively

Competence-Gated Pooling of Language Models and Priors for Event Forecasting

Abstract: In hybrid forecasting, a language model is often one of several available signals. A system may already have a market, crowd, or statistical forecast and must decide whether the model adds useful information or should be ignored. The relevant target is therefore not standalone model accuracy, but relative competence, defined as the model's marginal value beyond the available external forecast. Under Brier loss, we characterize when model disagreement can improve an external forecast and derive the gain from using domain-specific rather than global pooling weights. We then introduce a competence gate that estimates domain-level source weights from resolved outcomes, shrinks uncertain estimates toward a global weight, and recalibrates the pooled forecast. Across 2,357 resolved binary questions and five language models, the gate improves the main external baseline from 0.0771 to 0.0732 Brier and significantly outperforms global forecast combinations. The gain remains significant under leakage controls and against a leakage-safe time-series prior on the pooled structured set, with separate evidence on FRED. In contrast, the gate gives no significant improvement on the official ForecastBench market subset, where it largely defers to the market. Across four Qwen models, verbal confidence does not reliably identify when the model outperforms the external forecast, while outcome-estimated competence supports better abstention decisions. These results provide a practical approach for selective model use based on measured marginal value.

Thu 10 SeptArtificial Intelligence
The gist
Forecasting the outcomes of events is often done by combining various prediction sources like markets or crowds. The researchers studied how language models can add value when combined with these other forecasts, focusing on when to trust the model's information. They developed a method that measures how competent the language model is in a specific domain and uses that to decide how much weight to give its predictions. This approach improved forecast accuracy on many tasks by using the model selectively rather than always or never. They also found that simply using the language model's verbal confidence was less reliable for deciding when to listen to it.
Open → 2609.12101v1

Sparse vectors enable fast corporate event detection from SEC filings

A Training-Free, Alignment-Free Approach to Corporate Intelligence: Application to SEC Filings

Abstract: High-dimensional dense text embeddings and large language models face real obstacles in financial-disclosure analysis: context-window limits, hallucination risk, high computational cost, and the arbitrary rotation of vector spaces across independently trained models. We present a training-free, alignment-free framework for corporate intelligence built on deterministic sparse seed vectors. Hashing word strings into a fixed high-dimensional basis places all documents and all temporal epochs in a common coordinate system by construction, removing any need for training or alignment. Accumulating these seed vectors across sentence contexts yields corpus-specific semantic signatures that compose linearly, supporting sub-second document comparison, issuer fingerprinting, tracking of how an issuer's vocabulary shifts between filings, and thematic sentence extraction, all on ordinary CPU hardware. Demonstrating the approach on a multi-year corpus of SEC filings (10-K, 10-Q, 8-K), we show how material corporate events, among them Boeing's 737 MAX crisis, Intel's supply-chain disruptions, and Bunge's acquisition of Viterra, emerge as distinct, interpretable semantic profiles, each traceable to the exact source sentences that produced it, with no domain-specific training and no LLM inference.

Thu 10 SeptComputation and Language
The gist
Analyzing financial reports with popular AI models can be slow, costly, and sometimes inaccurate. The authors introduce a new way to study corporate documents without the need for training or complex model alignment, using a method that converts words into simple, consistent codes in a big space. This lets them quickly compare documents and spot important events, like crashes or acquisitions, by looking at the exact sentences where these changes happen. Their approach works on regular computers and avoids usual problems in AI analysis.
Open → 2609.11620v1