Small-Cap Profitability and Bollinger Band Stock Screening

Summary

This Chinese stock-screening note describes a rules-based approach that combines price movement, Bollinger Bands, company size, and profitability. It looks for stocks with above-average daily range, a close between the Bollinger middle and upper bands, market capitalization below 10 billion yuan, and positive profits. The intended rationale is to find relatively strong price action among smaller companies that are not reporting losses.

The post includes formula and Python examples, but the examples do not consistently implement the stated rules: the Python uses a different historical price check and references the first row for some price conditions. It provides no backtest results or evidence that the screen predicts gains. The author notes that a size cap can exclude larger quality firms, technical signals can be unreliable in volatile or falling markets, and short-term filters may miss companies with stronger long-term prospects. Suggested refinements include adding fundamental and market-attention measures and revisiting the size threshold.

Key ideas

• The screen combines above-average daily range with a close between the Bollinger middle and upper bands.
• It limits candidates to companies below 10 billion yuan in market capitalization and with positive profits.
• The document provides formula and Python examples, though the implementation does not fully match the stated screening logic.
• The post gives no performance test and warns that size and short-term technical filters can exclude promising stocks or misfire in declining markets.

Tags

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