In Barardehi, Yashar and Bogousslavsky, Vincent and Muravyev, Dmitriy, What Drives Momentum and Reversal? Evidence from Day and Night Signals (February 6, 2023, SSRN) the authors posit that momentum is entirely an intraday phenomenon (summary).
The authors split the standard past-return momentum signal into its intraday and overnight components and test which piece actually predicts future returns. They find that intraday-signal momentum works – stocks with high past intraday returns keep outperforming – while past overnight returns show no significant predictive power for future returns.
What we found with Indian stocks:
tl;dr: while overnight returns under-perform, intraday returns also under-perform a “total” (close-to-close) return ranking scheme.
Code and charts on github.