Upstart Shares Plunge 7.24 as $450M Volume Surge Propels It to 283rd in U.S. Liquidity Rankings

On October 10, 2025, Upstart (UPST) closed at a 7.24% decline, marking its largest single-day drop in recent months. Trading volume surged to $0.45 billion, a 48.78% increase from the prior day, placing it 283rd among U.S. equities in terms of liquidity. The sharp selloff occurred amid a broader market selloff, with investors reassessing risk exposure in the face of rising Treasury yields and tightening credit conditions.

Analysts noted the volatility reflected mixed signals from Upstart’s recent business developments. While the company’s AI-driven lending platform continues to gain traction in the fintech sector, concerns over macroeconomic headwinds and regulatory scrutiny in the consumer finance space have weighed on sentiment. The spike in volume suggests heightened short-term trading activity, though institutional positioning remains largely unchanged based on available data.

To run this test rigorously I need to lock down a few practical details up-front: Universe – Do you want all U.S. listed common stocks (NYSE/Nasdaq/Amex), or a defined subset such as S&P 1500 / Russell 3000? ADRs, ETFs and preferred shares are normally excluded – is that acceptable? Portfolio construction – Equal-weight each of the 500 names selected every day (typical), or volume-weight them? Rebalance daily at the close: buy at today’s close, sell at tomorrow’s close (so one-day holding period). Any transaction-cost estimate (e.g., 2 bps per side) you’d like applied? Data frequency / survivorship bias – Our default is to work with split- and dividend-adjusted daily closes and volumes, using a survivorship-bias-free universe (i.e., delisted stocks are kept in the sample). OK to proceed with that? Once I have those three points confirmed I can generate the daily trade lists, build the equal-weight (or volume-weight) portfolio, and run the full return / risk analysis from 2022-01-03 through the latest available trading day.