‘Crazy' investors are betting too much on the U.S. stock market

HSBC argues a roughly 60% allocation to U.S. equities in a global portfolio is reasonable, citing lower historical risk (using monthly returns since end-1987) and faster U.S. earnings growth, while cap-weighted indices now assign the U.S just over 60% of global market cap (72% of MSCI World developed-market exposure). Goldman and Vanguard data show retail investors are even more U.S.-biased (78% average equity allocation; 87% at Vanguard), but AQR and the author warn that U.S. outperformance since 1990 largely reflects valuation richening and that the HSBC time frame is cherry-picked. The piece recommends more international diversification (e.g., equal-weighted MSCI World which would be ~40% U.S. / 60% non-U.S. developed, with a 16% weight to Japan) to mitigate concentration and valuation risk.

Analysis

Market structure: The dominant winners from a reallocation away from U.S. cap-weighted exposure would be developed‑ex‑US ETFs (e.g., EFA/VEA), Japan (EWJ) and equal‑weight US products (RSP); index providers (MSCI) also gain from new benchmark demand. Direct losers are mega‑cap tech (QQQ constituents) and US‑centric retail allocations that carry 70%+ domestic equity exposure; expect cap‑weighted passive flows to slow if valuation discipline returns.

Risk assessment: Tail risks include a rapid US tech rerating (10–30% shock), a strong USD that erodes ex‑US returns, or a Fed policy surprise that reignites risk appetite and keeps US multiples elevated. Over days–weeks expect volatility spikes in QQQ and options; over 6–24 months the valuation mean‑reversion trade (ex‑US catching up or US multiple compressing) is the dominant high‑probability scenario. Hidden dependencies: currency hedging, tax/rebalancing calendar effects and passive‑flow stickiness can delay reallocation by quarters.

Trade implications: Implement size‑controlled rotation: buy EFA/VEA and RSP while trimming QQQ/SPY exposure; consider QQQ downside protection with 1–3 month put spreads financed by short EFA call spreads. Pair trades (long RSP, short QQQ) capture de‑crowding of mega caps; scale in over 4–12 weeks and target relative outperformance of 5–15% over 3–12 months.

Contrarian angle: Consensus underestimates inertia of passive flows and currency risk; the market may underprice a gradual 10–30% relative reallocation toward equal‑weight/ex‑US over 12–36 months. Historical parallels: post‑regime cycles (post‑1990s Japan, post‑2000 US) show multi‑year reversals — size your positions to survive a drawn‑out reversion and hedge USD exposures.

Key Decisions for Investors

• Establish a 2–4% portfolio long position in iShares MSCI EAFE ETF (EFA) or Vanguard FTSE Developed (VEA), scale into 50bp tranches weekly over 8 weeks, stop‑loss 12% absolute; target hold 12–24 months to capture valuation convergence.
• Initiate a relative‑value pair: Long Invesco S&P 500 Equal Weight ETF (RSP) 2% vs short Invesco QQQ Trust (QQQ) 2% notional; horizon 3–9 months, trim if the pair moves favorably by 10% or widen hedge if adverse by 8%.
• Buy a 1–3 month QQQ put spread (buy 5% OTM, sell 10% OTM) sized to 0.5–1% of portfolio premium to cap downside if mega‑cap derating begins; consider funding by selling EFA 1–3 month call spreads.
• Take a tactical 0.5–1% long position in MSCI Inc. (MSCI) for 6–12 months to capture potential product/benchmarking demand if allocations shift; review after quarterly AUM/ETF flow prints and rebalance thresholds.