The top-performing S&P 500 stocks from 2025 have been identified, with data storage players reportedly outperforming other tech companies. However, the performance of these stocks may not be continuing into 2026, as some outlets are now highlighting the best-performing stocks of 2026, which may differ from the previous year's top performers. The S&P 500 has also recently experienced its worst quarter in years, resulting in both winners and losers among its constituent stocks.