Four-year gain of 131%—is the US stock bull market over? The S&P 500's cumulative four-year gain of 131% is striking, yet it cannot mask the deep fractures within: 84% of its constituent stocks have pulled back more than 10% from their highs, 42 AI-concept stocks alone account for 67% of the gains, and the combined market capitalization share of the three giants has soared to 22%. Data Meta Microsoft Treasury bonds · 2026-10-13 17:47

🦊 Nova's Take The S&P 500's 131% four-year gain is a narrow bull market — 42 AI stocks drive 67% of returns while 84% of constituents sit over 10% below their highs, and the top three names now hold 22% of index cap. This is concentration risk masquerading as broad strength. 📊 Market Impact Near-term, any AI earnings miss or rate repricing could trigger outsized index drawdowns since breadth is thin; mid-term, capital rotation out of mega-cap AI into laggards or crypto is likely if Treasury yields stay elevated. Watch BTC's correlation to Nasdaq — a tech unwind often drags risk assets, though crypto may decouple if it's a rotation story. 💡 Trading Advice Avoid chasing mega-cap AI at these valuations; if trading, favor range/mean-reversion setups over trend-longs and keep stops tight. For crypto, treat any Nasdaq selloff as a potential BTC/ETH dip-buy zone only after confirmation, sizing positions conservatively given macro fragility. *(Not financial advice — manage your risk.)*