Analysis of Historical S&P 500 Strength on Dec. 26 (Post-Christmas Trading Day)

This analysis is based on a MarketWatch report [1] highlighting Dec. 26 as the S&P 500’s historically most reliably positive trading day. Historical data from Bespoke Investment Group [2] shows that in the 39 years since 1953 when markets were open on Dec. 26, the S&P 500 declined only 6 times (max drop <0.5%), with an average gain of 0.5% and median gain of 0.4%. Dec. 26 falls within the Santa Claus Rally period (last 5 trading days of the year + first 2 of the new year), where the S&P 500 has averaged 1.3% returns with 78% positive results since 1950 [3]. As of Dec. 24, 2025, the S&P 500 closed at 6,936.60 (+0.46% for the day) after a 10-day uptrend [0], aligning with seasonal positive sentiment. Affected instruments include the S&P 500 (^GSPC), Dow Jones Industrial Average (^DJI), and NASDAQ Composite (^IXIC) [0].

1. Dec. 26 stands out with a 84.6% positive rate and limited downside (max decline <0.5%), making it the most consistent positive day of the year for the S&P 500 [2].
2. Recent bullish momentum (10-day uptrend, Dec. 24 record intraday high) could reinforce seasonal positivity on Dec. 26 [0][3].
3. Potential drivers of Dec. 26’s strength (unconfirmed by the report) include light trading volume, year-end window dressing, and positive holiday consumer sentiment [0].
4. Low post-holiday volume on Dec. 26 may amplify price movements, increasing both upside and downside volatility [4].

• Opportunities
  : The strong historical track record suggests potential positive returns, especially amid the current uptrend [2][0].
• Risks
  :
  • Seasonal trends are historical tendencies, not guarantees—past performance does not ensure future results [2].
  • Low trading volume could lead to unexpected price swings [4].
  • External shocks (geopolitical events, surprise data) released during the holiday period may disrupt the pattern [0].

Dec. 26 has been the S&P 500’s most reliably positive day since 1953 (84.6% positive, 0.5% average gain) and falls within the Santa Claus Rally (78% positive, 1.3% average return). The index was in an uptrend as of Dec. 24, closing at 6,936.60 (+0.46%). While seasonal trends are encouraging, decision-makers should prioritize real-time data, liquidity levels, and potential external shocks on Dec. 26.