argenx's 120% volume surge propels it to 404th trading rank despite 2.56% price decline

On Sept. 25, 2025, argenx (ARGX) traded with a volume of $280 million, a 120.03% increase from the previous day’s activity. The stock closed 2.56% lower, ranking 404th in trading volume among listed equities. The surge in liquidity suggests heightened investor attention despite the downward price movement.

The stock’s performance appears linked to strategic positioning by traders capitalizing on its recent volatility. With a sharp rise in daily turnover, the security attracted speculative activity that often precedes short-term directional shifts. The volume spike outpaced its typical trading pattern, indicating potential accumulation or distribution phases among institutional players.

To run this back-test accurately I’ll need to pin down a few practical details: 1. Universe to rank • Do you want to look at all U.S. exchange-listed common stocks, or limit it to a well-defined set such as the Russell 3000 or S&P 500 constituents? 2. Re-balancing mechanics • Should positions be opened at the close of day t (after we know that day’s volume ranking) and closed at the close of day t + 1? • Equal-weight each of the 500 names each day? 3. Benchmark / transaction costs • Any benchmark you’d like to compare against? • Should we include an estimate of trading costs or assume frictionless execution? Once I have those details I can generate the daily trade list and run the back-test from 2022-01-03 (first trading day of 2022) to the present.