According to @StockMKTNewz, the S&P 500 will announce which companies are being added today at 5:15 PM ET as part of its quarterly rebalance cycle that includes the first Friday of March and June, providing a time-certain catalyst for traders, source: @StockMKTNewz. Index changes typically force benchmark-tracking funds to adjust holdings and can concentrate liquidity into the closing auction on the effective date, creating short-term, flow-driven price moves that event traders target, source: S&P Dow Jones Indices, S&P U.S. Indices Methodology. Academic studies document abnormal returns and volume around S&P 500 additions and deletions, supporting event-driven strategies focused on announcement-to-effective windows and post-event reversals, source: Chen, Norli, and Wang (2004), Journal of Financial Economics. Because Bitcoin and U.S. equities have exhibited higher post-2020 cross-asset correlation, equity event volatility can influence crypto risk sentiment; BTC and ETH traders should monitor the announcement window and equity futures for spillover, source: International Monetary Fund, Global Financial Stability Report 2022.