UnitedHealth’s $4.33 Billion Volume Ranks 14th as Shares Drop 2.33% Amid Healthcare Sector Volatility

On September 16, 2025, UnitedHealth (UNH) saw a trading volume of $4.33 billion, ranking 14th among U.S. equities. The stock closed down 2.33%, reflecting heightened volatility in the healthcare sector amid broader market uncertainty.

Recent regulatory scrutiny over pricing practices and Medicaid reimbursement policies has weighed on investor sentiment. Analysts noted that evolving federal guidance on drug pricing could force adjustments to UnitedHealth’s revenue streams, particularly in its pharmacy benefits management segment. Market participants are closely monitoring upcoming Medicare negotiations, which may further clarify long-term financial implications.

Short-term technical indicators show declining momentum, with the stock testing key support levels. Institutional selling pressure appears concentrated in mid-to-large-cap healthcare names, though sector-wide weakness suggests broader macroeconomic concerns are outweighing company-specific factors at present.

To run this back-test robustly I need to pin down a few practical details and assumptions: 1. Universe • Should I use all U.S. listed equities (NYSE, NASDAQ & AMEX) or another market? 2. “Daily trading volume” definition • Rank by share volume, or by dollar volume (shares × price)? 3. Trade timing • Select stocks with yesterday’s data, buy at today’s market open and liquidate at today’s close (≈ 1-day holding period), or buy at yesterday’s close and sell at today’s close, or another convention? 4. Transaction costs / slippage • Assume zero for simplicity, or apply a specific cost per trade? 5. Portfolio weighting • Equal-weight the 500 names each day, or weight proportional to volume? Once these points are confirmed I can generate the trade signals and run the back-test from 2022-01-01 to the present.