Markets historically underperform on the Monday following the spring daylight-saving time change, with the S&P 500 posting an average loss of 0.28% since 1990. The trend affects major equities like Apple (AAPL) and energy benchmarks such as CL=F.
- S&P 500 has averaged a 0.28% decline on Mondays following the spring daylight-saving time change
- Apple (AAPL) has dropped 0.41% on average on these Mondays since 1990
- WTI crude futures (CL=F) have declined 0.15% on average on affected days
- The CBOE Volatility Index (^VIX) has risen 1.8 points on average on these Mondays
- No causal relationship has been established; the trend is purely statistical
- The pattern is not used in active trading strategies or risk modeling
The Monday after the U.S. shifts clocks forward one hour in spring has consistently ranked among the weakest trading days for the S&P 500 over the past three decades. Historical data reveals that this specific Monday has recorded an average decline of 0.28% across 34 occurrences since 1990, outperforming only one other day of the year in terms of negative returns. This seasonal pattern appears to impact major components of the index, including Apple (AAPL), which has shown a 0.41% average drop on the affected Mondays. Energy markets also reflect the trend, with theWTI crude oil futures contract (CL=F) declining by an average of 0.15% on these days, suggesting broader market sentiment may shift before the open. The phenomenon coincides with heightened volatility, as measured by the CBOE Volatility Index (^VIX), which has averaged a 1.8-point increase on these Mondays. While no causal mechanism has been identified, the recurrence of poor performance underscores a persistent behavioral pattern tied to calendar shifts rather than economic fundamentals. Despite the statistical anomaly, financial professionals caution against using the daylight-saving transition as a predictive tool. The effect, while measurable, does not reflect underlying market conditions and is not factored into algorithmic trading models or portfolio risk assessments.