US Market Volume Plummets 24 to 740M as Energy and Tech Shifts Send Stocks to 147th Rank

American stock closed with a trading volume of $0.74 billion on September 8, 2025, marking a 24.24% decline from the previous day's activity. The security ranked 147th in terms of trading volume across the market. Meanwhile, American Airlines Group (AMZN) fell 0.25% during the session, reflecting mixed market sentiment toward major consumer discretionary sectors.

Analysts noted that reduced institutional participation and a shift in thematic investments toward energy and technology sectors contributed to the subdued volume. The decline in trading activity aligns with broader market patterns where defensive positions gained traction ahead of macroeconomic data releases scheduled for the following week.

Backtest parameters require clarification on three key aspects: (1) universe definition—whether to include all U.S. listed stocks or focus on a subset like S&P 500 constituents; (2) execution timing—using end-of-day prices or next-day open-to-close returns; and (3) weighting methodology—equal-weight allocation or volume-based adjustments. A proposed approach involves treating the S&P 500 as a proxy for "top 500 by volume" with daily equal-weight rebalancing. Final parameters must be confirmed to ensure accurate signal generation and backtesting outcomes.