Screening Chinese Stocks for Intraday Abnormal Activity

Summary

This report outlines five high frequency stock factors based on intraday price behavior, price and volume changes, returns, relationships with the market, and sequences of trades. Its main method identifies stocks whose intraday returns relative to the Shanghai Composite differ from their own recent history. It then measures how much of the day’s trading time, volume, and absolute returns came from those unusual minutes, standardizing these proportions against a 40 day history to flag candidates.

A preliminary backtest on a CSI 500 stock universe compares three anomaly types: unusual time share, volume share, and cumulative price movement share. The report says all three showed excess returns against the CSI 300 and could help separate stocks by market direction. Time share anomalies had higher but more volatile excess returns, peaking at a reported point before declining; the other two were steadier but had lower cumulative excess returns. The evidence is preliminary, and the text notes market capitalization effects and raises, rather than resolves, whether time share signals have a short horizon.

Key ideas

• The method compares a stock’s intraday returns with the Shanghai Composite’s returns.
• It defines anomalies using unusual minutes and their shares of daily time, trading volume, and absolute returns.
• The three anomaly measures are standardized against each stock’s recent 40 day history.
• A preliminary test reports excess returns and stock separation, while also noting market capitalization effects.
• Time share anomalies were more volatile and their cumulative performance later declined.

Tags

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.