This past week, the stock market witnessed a notable downturn for several major large-cap companies. The period between October 20th and October 24th saw ten prominent firms facing substantial losses. This summary highlights these underperforming stocks and the contributing factors to their declines, ranging from adverse market conditions to company-specific news, prompting investors to review their portfolio allocations.
Weekly Market Downturn: Key Companies and Driving Factors
Between October 20th and October 24th, the market saw significant declines among several large-cap equities. Leading the list of underperformers was Oklo Inc., which registered a 15.15% drop. Quantum computing firm Rigetti Computing, Inc. also experienced a sharp fall of 17.94%, with reports suggesting potential U.S. government investment talks failing to buoy its shares. Semiconductor giant STMicroelectronics saw a 17.17% decrease after issuing fourth-quarter revenue projections that fell short of analyst expectations. Following closely, D-Wave Quantum Inc. declined by 17.57%.
In the energy sector, NuScale Power Corporation plunged by 18.53% after Citigroup downgraded its rating from Neutral to Sell and adjusted its price target downwards. Footwear and apparel company Deckers Outdoor Corporation faced a 13.33% loss, attributed to a weaker-than-anticipated fiscal year 2026 sales forecast and subsequent analyst downgrades. Fermi Inc. also saw a 14.71% reduction in its stock value. The precious metals mining sector was impacted, with Harmony Gold Mining Company dropping 13.16% as gold and silver prices retracted from recent highs, despite general macro uncertainty favoring safe-haven assets. MP Materials Corp., a rare earth mineral company, recorded an 11.75% decline, possibly influenced by a new U.S.-Australia agreement aimed at boosting rare earth supplies. Lastly, AST SpaceMobile, Inc. fell by 14.75% following its announcement of a proposed private offering.
The market's volatility during this period underscores the critical importance of diligent research and a diversified investment strategy. The varied reasons for these declines—from corporate guidance and analyst ratings to broader commodity trends and strategic corporate actions—illustrate the complex interplay of factors influencing stock performance. Investors should consider these events as a reminder to continuously assess their holdings and stay informed about both company-specific developments and wider economic shifts.