HSBC Shares Plunge 5.83% as Trading Volume Surges to $2.2B Ranking 486th in Market Activity

On October 9, 2025, HSBC shares closed with a 5.83% decline, marking the largest single-day drop in recent weeks. Trading volume surged to $0.22 billion, a 178.26% increase from the previous session, ranking the stock 486th in trading activity across the market. The sell-off reflected heightened investor caution amid shifting macroeconomic expectations and sector-specific pressures.

Recent regulatory scrutiny over capital adequacy standards and evolving interest rate forecasts contributed to the downward momentum. Analysts noted that the bank's exposure to emerging market currency fluctuations, combined with unresolved litigation risks, amplified volatility. A midday report highlighted potential restructuring costs linked to digital transformation initiatives, further weighing on sentiment.

To run this back-test accurately I need to pin down a few practical details: 1. Stock universe • All U.S. common stocks (NYSE + NASDAQ) – or a specific index/segment? • Should ETFs, ADRs, specials (e.g., SPACs) be excluded? 2. Price used for entry/exit • Buy at today’s close and sell at tomorrow’s close (typical) • Or buy at next day’s open and sell at next day’s close/open? 3. Weighting scheme • Equal weight across the 500 names each day • Volume-weighted or market-cap-weighted? 4. Transaction costs / slippage • Ignore for now (pure signal) • Or assume a fixed bps cost per trade? Once I have those choices I can pull the volume data, form the daily portfolios, and run the one-day hold back-test from 2022-01-03 through today.