Multiple Companies Added to Various S&P Indices

S&P Dow Jones Indices announced a sweeping quarterly rebalance effective today (June 22) that reshuffles names across the S&P 500, MidCap 400, and SmallCap 600. The biggest move in the primary index: MRVL (Marvell Technology, ~$265B market cap) and Flex Ltd. join the S&P 500, replacing Pool Corp. (POOL) and The Campbell's Company (CPB), both descending to the SmallCap 600. The rebalance was announced June 5, giving passive funds roughly two weeks to position.

In the MidCap 400, ROKU joins alongside Coeur Mining (CDE), Semtech (SMTC), Sanmina (SANM), and Viavi Solutions (VIAV). Roku's inclusion is notable timing: it coincides with Fox Corporation's announcement that it is acquiring Roku at $160/share — index buying is now layering on top of M&A-driven demand for the stock. Eastern Bankshares (EBC) and Rush Street Interactive (RSI) are among the 16 companies moving into the SmallCap 600.

The S&P 500's three largest passive ETFs — VOO (~$1 trillion AUM), IVV (~$861B), and SPY (~$786B) — create mechanical buying pressure as they rebalance to include MRVL and FLEX. Marvell surged ~57% in the 17-day window between announcement and inclusion, a pattern that historically sees "sell-the-news" mean reversion once index funds have fully repositioned.