Despite Market Gains, Top Stocks Plummet in 2025

As of December 5, 2025, the S&P 500 index has demonstrated a robust year-to-date gain of 16.81%. However, this average performance masks considerable individual stock downturns, with several prominent companies experiencing significant losses. Among the worst performers is Fiserv, whose stock plummeted approximately 70% by December 5. Factors contributing to this sharp decline included a reduced revenue forecast and slower growth in its merchant-services segment.

The digital advertising sector also saw major setbacks, with The Trade Desk down around 67%. Increased competition from major players like Amazon has impacted its revenues, leading investors to view the stock as overvalued due to diminished future earnings prospects. Similarly, Deckers Outdoor, known for its popular UGG and Hoka brands, has fallen approximately 57% amid concerns over slowing growth and reduced consumer spending on discretionary items.

Research and consulting firm Gartner, despite its strong industry standing, has also faced pressure, with its stock down about 52%. This decline is seen as potentially cyclical, as companies often cut back on advisory services during economic uncertainty. These significant drops underscore the volatility within the market, even during periods of overall positive index performance.