Count the bets, not the names.
01
Forty lines only save you from one of them blowing up. They do nothing when the whole mid-and-small universe sells off in the same fortnight. Jan and Feb 2025, down 10.9 then 14.1, all forty fell together. That is what a 26 percent hole is made of.
02
It wins more often than the 5-stock card, 64.37 of weeks against 59.39, and still falls deeper. The down weeks arrive clustered. Read the worst week, minus 13.44, not the hit rate.
03
Same Sharpe as the concentrated card, 1.61. Breadth did not even buy a better risk-adjusted number. Size it as a satellite and judge it by the fall you have to sit through, not the 48.98 headline.
Diversification is a count of bets, not a count of names. Forty tickers that rise and fall in the same week are one bet wearing forty jerseys.