Nasdaq Slumps 0.48% as Volume Plummets 34.57% to Rank 459th in Activity

Nasdaq closed on Sept. 25 at a 0.48% decline, with total trading volume of $0.24 billion—a 34.57% drop from the previous day—ranking it 459th in market activity. The benchmark index faced broad-based selling pressure amid mixed earnings reports from key tech holdings and macroeconomic uncertainty.

Market participants noted declining liquidity as volume concentrations shifted toward mid-cap growth stocks, while large-cap tech components underperformed. Analysts attributed the weakness to profit-taking following recent volatility in AI sector valuations and regulatory scrutiny of data privacy frameworks.

Back-testing parameters for a volume-weighted "Top-500-by-volume" strategy require clarifying: (1) universe scope (entire US market vs. S&P 500/Russell 3000), (2) weighting methodology (equal vs. market-cap/volume-based), (3) execution timing (close-to-close vs. open-to-close), (4) transaction cost assumptions, and (5) benchmark selection (e.g., SPY). These parameters will determine the pipeline's data retrieval and performance evaluation framework.