The Buffer Band Would Have Caught Forty Percent

When I ran the buffer-band simulation for the Same Stock, Twice piece, I expected a reduction. I did not expect forty percent. The rule was simple: a stock gets reclassified only when it has clearly crossed a boundary and stayed there for more than one consecutive update. Aggregate bucket shock across observable scheme-months dropped from 21.45 percentage points to 13.23.

The implementation would not change the categories. It would not relax compliance floors. It would only change which stocks cross the line and how often they cross back. Morningstar already does this for its style boxes, in a context where the stakes are lower. AMFI's list, because of the 2017 architecture, has operational consequences that make the argument for hysteresis stronger, not weaker.