Alaska Air’s Shares Plunge 6.69% on 89.83% Volume Surge, Rank 332nd in U.S. Trading Activity

On September 15, 2025, , . The stock ranked 332nd in trading activity among U.S. equities. The drop followed reports of a significant operational disruption at its main hub, which temporarily grounded multiple flights and triggered a surge in customer service inquiries.

The airline’s shares faced pressure as analysts highlighted the potential impact of prolonged operational instability on fourth-quarter revenue projections. While the company has yet to provide a detailed timeline for resolving the issue, industry observers noted that repeated service interruptions could erode customer confidence and increase restructuring costs. Short-term volatility appears tied to the immediate operational challenges rather than broader industry trends.

To set up this back-test accurately, I need to confirm a few implementation details: (1) Market universe: Should we rank all U.S. listed common stocks (NYSE + NASDAQ + AMEX), or a different universe (e.g., , ? (2) Trade timing convention: After ranking by today’s trading volume, do we buy at today’s close and sell at tomorrow’s close, or buy at tomorrow’s open and sell at tomorrow’s close? (3) Position sizing: Equal-weight the 500 names each day (default), or use another weighting? (4) Transaction costs: Should we include an estimate (e.g., , or ignore costs? Once confirmed, the back-test will proceed.