Papers for

algorithmic trading developers

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.

Online method adapts portfolio window size to reduce trading costs

Cost-Sensitive Online Window Size Selection for Portfolio Management

Abstract: This paper investigates cost-sensitive online window size selection for portfolio management under changing market conditions. Specifically, we propose a two-level framework that constructs portfolios using candidate window sizes and dynamically aggregates them through online learning. By treating candidate window sizes as ``experts,'' we dynamically update their aggregation weights using turnover-inclusive losses. Moreover, we derive finite-horizon cost-sensitive tracking-regret bounds that account for turnover of the aggregated portfolio, with static regret as a special case. Under bounded losses and cost rates, suitably tuned Fixed Share achieves asymptotically no tracking regret for sublinear switching budgets, with Hedge covering the static case.

Thu 24 SeptMachine Learning
The gist
Choosing how far back in time to look at stock prices matters for investment strategies, especially when markets change. This paper shows a new way to automatically pick and combine different time windows so portfolios adapt better over time without excessive trading costs. The authors treat each window choice as an expert and update their influence based on both performance and trading costs. Their approach comes with mathematical guarantees on how well it tracks the best switching strategy under realistic cost conditions.
Open → 2609.29887v1

Agent system uses past trading memory to improve financial decisions

Agent Memory with Episodic Retrieval for Financial Decision-Making

Abstract: Large language models (LLMs) have demonstrated strong capabilities in financial analysis and reasoning, inspiring recent advances in agent-based trading frameworks. While these systems show promise, prior approaches either emphasize long-horizon forecasting or operate as stateless analyzers, limiting their applicability to the demands of trading in complicated settings. To address these gaps, we introduce META (Memory Enhanced Trading Agent), the first RAG-like episodic-memory-augmented multi-agent framework for financial decision making. META integrates a family of specialized indicator agents (e.g., Trend, MACD, Stochastic, RSI, SMA, AVWAP, Heikin-Ashi) with a Decision Agent that fuses their reports, and a Memory module that retrieves and updates past trading episodes encoded as market state embeddings with outcomes and reflections. By recalling relevant experiences and adaptively reweighting signals under similar market regimes, META achieves improved directional accuracy and robustness under short-horizon evaluation. Our results demonstrate that episodic memory provides a powerful mechanism for regime-aware, interpretable, and low-latency decision-making in trading and decision making. The code of this project is released on GitHub.

Wed 23 SeptArtificial Intelligence
The gist
Financial trading is complicated and requires quick decisions based on lots of information. The authors created META, a system that remembers past trading experiences and uses that memory to make better decisions today. META combines several specialized expert agents with a decision maker and a memory module that recalls similar past market situations. This helps the system adapt to changing market conditions and make more accurate short-term predictions.
Open → 2609.28771v1

AlphaRJM improves formulaic alpha discovery using reward-jump memory

AlphaRJM: Reward-Jump Memory for Stochastic Return-Guided Alpha Discovery

Abstract: Formulaic alpha discovery is a pool-dependent symbolic search problem in which informative feedback is observed primarily when a complete expression is evaluated. This delayed feedback creates two coupled difficulties: the retained alpha pool does not preserve the full history of realized evaluation feedback, and the value of an intermediate construction action is uncertain because its consequence depends on the formula eventually completed. We introduce AlphaRJM, which addresses these difficulties through Reward-Jump Memory, an event-driven latent state that remains fixed during token construction and updates only at terminal evaluation events using the realized pool reward and evaluation outcome, and an action-conditioned SDE return critic that represents future discounted discovery returns with stochastic particles. The particles guide action selection through their mean and uncertainty and are learned using a distributional Bellman objective combining energy-distance matching, mean calibration, and jump regularization. Empirically, AlphaRJM delivers strong and stable gains across multiple equity universes, forecasting horizons, and random seeds, while ablations confirm the complementary roles of persistent evaluation history, stochastic return modeling, and distributional supervision.

Tue 8 SeptMachine Learning
The gist
Finding formulas that predict stock returns is tricky because feedback only comes after a complete formula is evaluated, making it hard to judge partial progress. The authors introduce AlphaRJM, which keeps track of rewards from complete formulas in a special memory that only updates when a formula finishes. It also models future payoffs with a technique that accounts for uncertainty. Together, these approaches help select better actions when building formulas and lead to more stable and better predictions in stock markets.
Open → 2609.08581v1