Is the Buffett Indicator Flashing a Warning Sign to Stock Market Investors?

The S&P 500 returned 322% over the decade through Oct. 23, while the Buffett indicator stands at 234% and the CAPE ratio at 40.6—both elevated readings that have raised valuation concerns. The article argues the Buffett indicator is an imperfect timing tool because it excludes U.S. companies’ overseas revenue and does not account for expanded liquidity; M2 has risen from $6.9 trillion to $23.3 trillion. It recommends patient, long-term investing rather than attempting to sidestep a potential downturn.

Analysis

The valuation signal is more useful for setting long-run return expectations than for timing a near-term drawdown. The global-revenue objection weakens the Buffett indicator’s denominator, but does not neutralize high equity prices relative to earnings; CAPE is the more direct warning, although still a poor calendar for a correction. Likewise, a larger M2 stock is not equivalent to a durable flow into equities: marginal liquidity, real yields, credit conditions and risk appetite matter more for the next few quarters.

The second-order risk is concentration and feedback. If AI-related spending disappoints, the effect could reach suppliers and infrastructure providers through lower order expectations, while pressure on a few large index constituents mechanically weighs on cap-weighted benchmarks. That makes index-level exposure more vulnerable than the broad “U.S. economy” framing implies. Conversely, sustained AI monetization—not capex announcements alone—could support earnings and make valuation compression gradual rather than abrupt.

Days to weeks: valuation alone is not a short catalyst. Over 1–3 months, watch real yields, market breadth and large-company guidance on AI spending and returns. Over 6–18 months, the key test is whether AI investment converts into durable revenue and earnings. The article’s historical rolling-return argument is not a guarantee and says little about interim drawdowns or future starting valuations. No company-specific margins, consensus positioning or option pricing are provided, so avoid asserting a mispricing or sizing a directional short.

Key Decisions for Investors

• Do not short the S&P 500 solely on the valuation indicators. For existing U.S. equity exposure, consider a gradual rebalance from cap-weighted exposure toward equal-weight exposure; this reduces dependence on a narrow group of mega-cap leaders but can lag if those leaders continue to dominate.
• If AI-linked exposure is concentrated, use a defined-risk put spread on a broad U.S. equity index as a conditional 1–3 month hedge only if implied volatility and hedge cost are acceptable. Keep it limited: valuation can remain elevated, and no near-term catalyst is established here.
• Set an alert for a combination of deteriorating market breadth, higher real yields, and downward revisions to AI-related revenue or spending guidance. That combination would strengthen the case for reducing high-beta, valuation-sensitive exposure; broadening participation and stable earnings revisions would weaken it.
• For a 6–18 month reassessment, verify whether AI investment is producing realized revenue and earnings rather than relying on announced spending, and track liquidity through rates and credit conditions rather than M2 alone. A sustained earnings slowdown or material real-yield rise would falsify the patient, valuation-is-not-a-timing-signal base case.