Research on portfolio selection based on machine learning and asset characteristics
With the explosive growth of investable assets and asset information,portfolio se-lection faces the dual challenges of high dimensionality in both assets and characteristics.This paper proposes a portfolio selection framework based on machine learning and asset character-istics.Leveraging the inherent advantages of machine learning,the framework utilizes asset characteristics to directly predict portfolio weights,bypassing return distribution prediction in the conventional two-step portfolio management paradigm.The framework is applied to asset al-location research in the Chinese stock market.The research results show that:1)The proposed investment strategies capture incremental information within high-dimensional characteristics and uncover both linear and non-linear relationships between asset characteristics and portfolio weights,resulting in a significant enhancement of investment performance.2)Trading friction-related characteristics are the most important indicators for predicting portfolio weights.3)These strategies yield higher returns on stocks with stricter arbitrage restrictions while exhibit-ing lower sensitivity to changes in macroeconomic conditions.Under other economic constraints,these strategies remain robust.This paper expands the research framework of modern portfolio theory,contributing to the development of artificial intelligence and quantitative investment.