32 research outputs found
Stock portfolio construction in the Korean stock market applying XGBoost Classi๏ฌer
MasterThe stock selection is identifying the stocks suitable for investors to construct a portfolio. The process of stock selection generally compares the value, quality, and soundness of the ๏ฌrms listed in the stock market. It is known that the analysis of the ๏ฌnancial ratios recorded in each companyโs financial statements is useful. In addition, several studies have shown that ๏ฌnancial statements such as PER, PBR, PSR, F-score, and size can produce excess returns in stock investment. However, when investing in a company selected through ๏ฌnancial statement analysis, it is reasonable to invest in referring to previous price movements and technical indicators recorded on the stock chart. Therefore, we use the excess return ๏ฌnancial indicators and technical indicators encoded by classical trading strategies as the features of machine learning. This paper analyzes all the stocks in the KOSPI and KOSDAQ market and selects the candidates to construct an optimal portfolio by using XGBoost classi๏ฌer. Especially, we apply two di๏ฌerent methods to improve the predictability of XGBoost classi๏ฌer and use them to construct our models. If the number of selected stocks remains reasonable, adjusting the threshold on the prediction probability of XGBoost classi๏ฌer is meaningful to increase the precision. We con๏ฌrm this relationship and use the new prediction thresholds. In addition, we select four encoded technical indicators based on feature importance and use it to get the ๏ฌnal candidates. This is to decide which trading strategies should be mainly used in each trading period. It is con๏ฌrmed that with this ๏ฌltering, the precision is mostly higher than that of the simple XGBoost classi๏ฌer. Finally, when monthly investing with the constructed portfolio by our models, it mostly outperforms our benchmark KOSPI index returns and gets su๏ฌciently good cumulative pro๏ฌts to invest. In conclusion, our models can e๏ฌectively help investors to make a rational stock investment portfolio