I’ll chime in here with another factor that can affect short-term momentum trades, especially sort of 9:30 – 1:30, and that is the overlap of different global markets. The first window from 9:30 – 11:00 often has a strong influence from international markets that have been trading for hours (like Europe and Asia). This can bring in loads of liquidity, often leading to sharper price action and clearer trends.
