Minimal Batch Adaptive Learning Policy Engine for Real-Time Mid-Price Forecasting in High-Frequency Trading
Adamantios Ntakaris, Gbenga Ibikunle
TL;DR
The paper tackles real-time mid-price forecasting in high-frequency trading by leveraging NASDAQ Level 1 LOB data across 100 stocks. It introduces ALPE, a batch-free, online RL agent that uses an MLP policy-value network and adaptive epsilon decay to directly predict mid-price adjustments from the current LOB state. Two feature spaces (Simple and Extended) and three input variants (Raw, MDI, GD) are evaluated against baselines (Naive, ARIMA, MLP, CNN, LSTM, GRU, RBFNN) using MSE, RMSE, and the proposed Relative RMSE (RRMSE), with ALPE consistently achieving superior accuracy. The work demonstrates ALPE’s robustness across trading volumes and suggests future directions, including multi-agent RL and Level 2 LOB processing, to broaden applicability in real-time market environments, with RRMSE providing a normalized performance lens.
Abstract
High-frequency trading (HFT) has transformed modern financial markets, making reliable short-term price forecasting models essential. In this study, we present a novel approach to mid-price forecasting using Level 1 limit order book (LOB) data from NASDAQ, focusing on 100 U.S. stocks from the S&P 500 index during the period from September to November 2022. Expanding on our previous work with Radial Basis Function Neural Networks (RBFNN), which leveraged automated feature importance techniques based on mean decrease impurity (MDI) and gradient descent (GD), we introduce the Adaptive Learning Policy Engine (ALPE) - a reinforcement learning (RL)-based agent designed for batch-free, immediate mid-price forecasting. ALPE incorporates adaptive epsilon decay to dynamically balance exploration and exploitation, outperforming a diverse range of highly effective machine learning (ML) and deep learning (DL) models in forecasting performance.
