S&P Indexes

The largest pool of benchmarked money in the world — and the only mega-index family still picked by a committee.

How it rebalances

• Quarterly rebalances effective after the close of the third Friday of Mar/Jun/Sep/Dec — always quad witching, concentrating the trade in the closing auction.
• Changes announced ~2 weeks (10 trading days) before the effective date.
• Committee-driven selection: additions can happen off-cycle any time; deletions from the 500 typically cascade into the MidCap 400 and SmallCap 600.
• Style indexes reconstitute annually at the December third-Friday close; Select Sector re-caps quarterly.
• Equal-weight S&P 500: each name resets to ~0.198% at each quarterly rebalance.

Upcoming

• Fri Sep 4, 2026 — September rebalance announcement.
• Fri Sep 18, 2026 — rebalance effective after the close.
• Fri Dec 18, 2026 — December rebalance + annual style reconstitution.

Full calendar →