Blooms drop as a result of the Russell big cap move
Partial explanation below:
The "Graduation" Liquidity Shift: When a stock grows aggressively and graduates from a small-cap index to a large-cap or mega-cap index, it can suffer a short-term drop in relative index weight. Even though the company is technically moving "up," it goes from being a massive fish in a small small-cap pond to a tiny fish in a massive large-cap pond, initially reducing its mandatory passive ETF allocation.
The final day of the Russell rebalance—historically the last Friday in June (like the recent June 26, 2026 rebalance)—regularly ranks as one of the highest trading volume days of the year.The Closing Cross Spike: To minimize tracking errors, passive managers flood the market at the exact closing bell. Exchanges like Nasdaq and the NYSE process $150 billion to $200+ billion in trading volume in a matter of minutes.