Screening Stocks by Amplitude, Main-Player Control, and Ownership Concentration

Summary

This note proposes selecting stocks with daily amplitude above 1%, a signal described as main-player control on the prior day, and shareholder concentration below 70%. It characterizes concentration as the share of total equity held by the largest holders and suggests that lower concentration may reduce concerns associated with highly concentrated ownership. The post also gives a sample Python filter using turnover, positive earnings multiples, ownership concentration, and exclusion of special-treatment stocks; these extra filters are not all part of its stated core rule.

The author cautions that amplitude alone does not capture overall risk, the control signal may be temporary, and a concentration reading below the threshold does not eliminate governance or control concerns. Fundamental, technical, and valuation factors, as well as risk controls, are suggested as additions. The document supplies no backtest, definitions for the control signal, or evidence that the screen produces returns, so its rationale and implementation need independent validation.

Key ideas

• The proposed screen combines amplitude above 1%, prior-day main-player control, and ownership concentration below 70%.
• The post describes concentration as the leading shareholders’ proportion of total shares.
• Its sample code adds turnover, earnings-multiple, and special-treatment filters beyond the stated core logic.
• The control signal may be short-lived, while amplitude and concentration thresholds do not capture all risks.
• No performance test or operational definition of the control signal is provided.

Tags

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