Percentile-Rank Momentum With Hysteresis: Low-Churn Signals [Aligrithm] Momentum is the oldest anomaly in the book, and a new momentum paper has to justify why it exists. Landolfi's percentile-rank framework does not sell you the momentum. It sells the plumbing around it: rank each move against its own sign-consistent history instead of a raw threshold, gate entries and exits with a hysteresis band so the signal stops flip-flopping, and validate with a grid of