IWM fell from 294.01 on September 2 to 290.64 on September 9, a decline of 1.9%, and traded 288.36 on September 10 for a further 0.8%. Over the same window SPY fell 0.4% and QQQ rose 1.0%. Small caps underperforming large caps by more than two percentage points in a week is the composition signal that the index level alone conceals, and it has now widened in two consecutive refreshes.