SanDisk Shares Plunge 9.85% on Surge in Trading Volume to $940M Despite Ranking 141st in Market Activity

On October 10, 2025, Sandisk (SNDK) closed with a 9.85% decline despite a surge in trading volume to $0.94 billion, representing a 104.62% increase from the previous day. The stock ranked 141st in terms of trading activity across the market. The sharp drop in price came amid mixed signals from sector dynamics and evolving investor sentiment toward technology infrastructure stocks.

Analysts noted that the heightened volume did not translate into a positive price movement, indicating potential profit-taking or short-term positioning adjustments. The stock's performance was largely attributed to broader market rotation rather than company-specific developments. Institutional traders appeared to rebalance exposure amid shifting risk appetite, with some funds reducing long positions in favor of more defensive assets.

Back-testing constraints highlight challenges in replicating portfolio strategies for Sandisk. Current systems allow analysis of single securities but cannot construct and rebalance a 500-stock, equal-weighted portfolio daily. Two feasible approaches include using a broad-market ETF as a proxy to evaluate timing logic or narrowing focus to a single high-liquidity stock for volume-based event testing. These methods aim to isolate key variables while maintaining analytical rigor within existing technical limitations.