This Market Signal Has Been 95% Accurate for Nearly 90 Years. What Investors Need to Do Now to be Ready

Historical data cited by Fidelity show the S&P 500 has risen in the 12 months after U.S. midterm elections 95% of the time since 1938, while the third year of a presidential cycle has averaged a 14.5% annual return since 1950. The article notes that midterm-election years have historically seen the S&P 500 gain about 6% from the end of September through year-end, despite September declines of 5% or more in 15 of the past 24 such years. It argues investors should remain invested in the current bull market through broad ETFs such as VOO and QQQ, citing large-cap technology fundamentals and AI-driven growth despite elevated valuation metrics.

Analysis

The calendar effect is a weak standalone alpha signal because it is widely known and can be front-run by systematic allocators. Its more useful implication is positioning: a late-September risk-off move without a concurrent deterioration in earnings revisions, credit spreads, or real yields would likely be a buyable dip into year-end. Conversely, a rally driven solely by election-season optimism leaves the index vulnerable because index-level returns are now unusually dependent on a narrow group of long-duration mega-cap growth stocks.

QQQ has greater upside beta than VOO/SPY if declining political uncertainty coincides with easing financial conditions, but it also carries the larger valuation-duration risk. NVDA and NFLX would benefit from renewed passive and momentum inflows, yet neither has a direct election-cycle earnings catalyst; the relevant question is whether AI capex guidance and consumer-discretionary spending estimates continue to rise. The claim that AI demand is unconstrained should not be underwritten without evidence of enterprise monetization, power availability, and sustained hyperscaler capex returns.

For the next 1-3 months, the key confirmation is broadening participation rather than another index rally led by the largest technology names. Improving equal-weight relative performance, stable high-yield spreads, and positive 2027 EPS revisions would support a cyclical year-end bid; a 25-50bp rise in real yields or widening credit spreads would likely overwhelm seasonal flows. Over 6-18 months, election-policy uncertainty can create sector dispersion in financials, industrials, healthcare, and clean energy, but the current information does not establish a directional policy trade.

Key Decisions for Investors

• Do not add outright index beta solely on seasonality. Set a tactical buy trigger for SPY or VOO on a 3-5% pullback only if HY credit spreads remain contained and forward EPS revisions are flat-to-positive; target a 2-4 month holding period, with thesis invalidated by sustained spread widening or negative aggregate guidance.
• Express any year-end risk-on view as long RSP / short QQQ rather than incremental QQQ exposure if mega-cap technology leadership remains narrow. This captures potential breadth normalization while reducing concentration risk; reassess if QQQ earnings revisions reaccelerate materially relative to the rest of the market.
• Maintain NVDA as an earnings-and-capex thesis, not a calendar trade. Add only following independently verifiable hyperscaler capex guidance and data-center revenue durability; use a defined-risk put spread or reduce exposure if real yields rise sharply and AI-related forward revenue estimates stop increasing.
• For existing long QQQ or NVDA exposure, purchase 2-3 month downside protection after a volatility-compressed rally rather than selling core holdings prematurely. The hedge is most valuable if the market prices a benign year-end outcome while policy headlines, rates, or credit conditions turn adverse.