According to @StockMKTNewz, AppLovin (APP) will become an S&P 500 constituent at the U.S. market open tomorrow, with the change effective on the opening print; source: @StockMKTNewz on X, Sep 21, 2025. Passive S&P 500 trackers such as SPY and VOO seek to replicate the index and will adjust holdings to include APP around the effective time, typically creating mechanical buy demand and elevated liquidity; sources: SPDR S&P 500 ETF Trust prospectus; Vanguard 500 Index Fund prospectus. S&P Dow Jones Indices implements constituent changes effective prior to market open on the announced date, concentrating trading activity in the implementation window; source: S&P Dow Jones Indices, S&P U.S. Indices Methodology and Corporate Actions Policies. Index addition events have historically shown short-term volume spikes and price effects around the effective window that traders may attempt to fade or follow intraday; sources: S&P Dow Jones Indices research on index rebalances; academic literature on index additions (e.g., Chen and Norli, 2004). For crypto, there is no direct on-chain impact, but cross-asset risk appetite around the U.S. cash open can coincide with BTC and ETH correlation shifts versus U.S. equities, so monitoring crypto liquidity during the opening hour is prudent; sources: Fidelity Digital Assets 2023 research on BTC–equity correlations; Coin Metrics correlation analyses.