BCA: US equities have already priced in a large share of AI’s expected gains. Approximately 25% of current market cap reflects multiple expansion since ChatGPT’s release. Bond yields are slightly higher over that period, so the rerating reflects a lower equity risk premium rather than cheaper discount rates. That leaves less room for disappointment if AI adoption, demand, or earnings fall short. Momentum and earnings still support the market, but the valuation cushion is now thin.