What's the Risk? 7 Numbers that Reveal Hidden Exposures in Today's Portfolios

Public-market portfolios may carry concentrated exposure to rates, expensive equities and the AI investment cycle despite appearing diversified.

• Markets entered 2026 expecting two rate cuts, but the Federal Reserve raised rates in September; by October 30, markets priced a 73% probability of another 25-basis-point hike in December, while the Bloomberg US Aggregate fell 3.5% in the third quarter.
• The Shiller CAPE ratio stood at 40.2x versus a 30-year average of 28.9x, while Baa corporate bonds yielded about 6% against a 5.4% forward earnings yield for the S&P 500.
• The 10 largest S&P 500 stocks, including Nvidia, Microsoft and Apple, generated 57% of the index's return in 2026 and represented 39% of its weight, while more than 80% of US companies with annual revenue above $100 million remained private.
• Hyperscaler operating cash flow is expected to rise from about $600 billion in 2025 to $2 trillion by 2030, creating downside for AI-linked equities and credit if that growth falls short or arrives later.
• Treasuries accounted for about 46% of the Bloomberg US Aggregate in October 2026, compared with about 24% for corporates, and AI-related issuance reached $332 billion, more than half of net investment-grade supply.
• The 36-month rolling stock-bond correlation peaked near 0.7 in 2024 and remained about 0.5, while private infrastructure and real estate showed correlations of 0.34 and 0.17 with US stocks and -0.12 and -0.23 with US bonds.

Takeaway: Investors should review whether their portfolios are mainly exposed to interest rates, AI borrowers and a small group of expensive stocks, then consider floating-rate credit, private equity, asset-backed finance, infrastructure, real estate and hybrid strategies as potential diversifiers, subject to manager selection, liquidity and private-market risks.