As 2025 draws to a close, the S&P 500 Index (SPX) finds itself in the spotlight, surging to fresh record highs and igniting investor interest across Wall Street. The final week of the year has delivered a classic ‘Santa Claus rally,’ with the SPX moving decisively above its previous resistance, despite mixed signals in the broader market. This momentum raises a critical question for traders and long-term investors alike: will this bullish run continue into 2026, or is a pullback looming?
According to Schaeffer’s Research, the SPX closed last Monday at 6,817, officially entering a historically bullish seasonal period. December’s second half typically averages a 1.30% return, and this year was no exception. A robust third-quarter GDP report provided additional support, echoing the script of holiday optimism. On December 24—a shortened session for Christmas Eve—the SPX pierced its late October intraday high at 6,920, marking a breakout after several failed attempts to clear the 6,900 threshold earlier in the month.
Market watchers have long observed the so-called ‘Santa Claus rally,’ a phenomenon characterized by sustained gains during the last five trading days of December and the first two of January. This year, calculations suggest the SPX could climb to around 6,967 by January 5, based on historical averages. Yet, as history teaches, the holiday effect is not a guarantee. Last year, the absence of a rally signaled short-term trouble, with the index declining the day after Christmas—a rare move given the day’s bullish track record since 1953.
Despite the holiday cheer, technical analysts remain cautious. Resistance looms overhead, particularly at the 7,000 mark—home to sold calls linked to J.P. Morgan’s quarterly expiration collar strategy. This level, just about 1% above Friday’s close, is not just symbolic; it could spark hesitation or a pivot, as seen in prior months when the SPX neared round year-to-date return levels. Should the index break through, analysts point to the 7,058 region as the next resistance, representing a 20% gain from last year’s close.
On the flip side, if this rally fails, support is expected around 6,760 and 6,790—areas defined by previous resistance and key moving averages. These levels could act as safety nets if momentum wanes, especially as short interest on SPX components has climbed 2.5% to multi-year highs, according to exchange data. Notably, total short interest is up 45% for the year, underscoring a market dynamic where short-covering rallies and brief pullbacks are increasingly common.
The broader context for 2025 has been overwhelmingly positive. TipRanks reports that the SPX is up 17.7% year-to-date, with the Dow Jones Industrial Average gaining 14.5%—its best run since 2021. The Nasdaq Composite led the charge, soaring 22.2%. This performance has been underpinned by strong demand for AI chip stocks, resilient metals markets, and stable economic data, helping the market weather periods of uncertainty.
Still, as futures trading opened for the last Sunday of the year, signals were mixed: SPX and Nasdaq 100 futures dipped slightly, while Dow futures ticked up. The week’s data calendar is light, but one key event remains—the release of the Federal Reserve’s December meeting minutes on Wednesday. Investors will be parsing this for clues on policy direction heading into 2026, mindful that any hint of tighter monetary policy could shift sentiment.
For those betting on the SPX’s next move, platforms like Polymarket have seen significant activity, with over $31,000 in volume wagered on whether the index will close higher or lower on December 29. The outcome will be determined by comparing the official closing price with the previous trading day, as published by the Wall Street Journal. If the price is unchanged, the market resolves evenly; if trading is disrupted or halted, the last valid price will be used for settlement.
As the year closes, the SPX stands at a crossroads—buoyed by bullish sentiment, technical breakouts, and strong fundamentals, yet shadowed by high short interest and looming resistance. Will the rally continue, or will the bears regain control as 2026 begins? The answer may hinge on the delicate balance between optimism and caution, with every tick of the index reflecting the collective hopes and fears of a market always looking one step ahead.
Given the record highs and sharp increase in short interest, the market is at a pivotal moment. While the technical and seasonal factors favor continued strength, elevated short positions and nearby resistance suggest investors should brace for volatility. The SPX’s fate in early 2026 will likely depend on both economic policy signals and the ability of bulls to overcome psychological and option-related barriers.