Screening for Stocks After a Limit-Down Opening Match

Summary

This document proposes a Chinese stock screen using three conditions: intraday amplitude above a threshold, a daily decline within a narrow band, and a previous day 9:15 opening match at the limit-down price. The rationale is that a sharp prior decline may create a rebound opportunity, while the current day’s movement identifies stocks with notable price activity. A Python example illustrates excluding certain listings and special-treatment stocks, then filtering on daily percentage change and the opening-match condition.

The article offers no historical test, return series, or evidence that the proposed rebound effect persists. It notes risks from poor liquidity, trading frictions, trading halts, and company-specific events, and suggests adding volume and valuation filters. Its example code does not visibly apply the amplitude condition, and the timing/data definitions would need validation before implementation. The screen should therefore be treated as a candidate-generation idea, not a complete or validated trading strategy.

Key ideas

• The proposed screen combines intraday amplitude, a constrained daily loss, and a prior limit-down opening match.
• The author interprets the prior limit-down event as a possible setup for a rebound.
• The example code filters daily returns and opening-match records but does not visibly implement the amplitude condition.
• Liquidity, execution, trading halts, and company events are identified as risks.
• No backtest or evidence of predictive performance is supplied.

Tags

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