CME Group Crumbles 1.61% as $600M Volume Ranks 212th in U.S. Equity Activity Amid Shifting Market Dynamics

CME Group closed down 1.61% on October 1, 2025, with a trading volume of $600 million—marking a 23.27% decline from the previous day's volume and ranking 212th in total trading activity among U.S. equities. The exchange operator's shares faced pressure amid mixed market conditions and sector-specific dynamics.

Analysts noted that macroeconomic uncertainty and shifting investor priorities weighed on market infrastructure stocks. While no direct earnings or regulatory developments were disclosed, broader market trends highlighted reduced liquidity in derivatives markets. The decline in CME's trading volume suggests reduced short-term speculative activity, though long-term fundamentals remain unaffected by the single-day drop.

To run this back-test accurately we need to pin down a few implementation details that aren’t fully specified yet: 1. Market universe • U.S. listed common stocks (default), or another market? • Do you want to exclude ETFs, ADRs, SPACs, etc.? 2. Volume definition • Share volume (shares traded) – most common, or • Dollar volume (shares × close price). 3. Weighting in the day-ahead portfolio • Equal-weight each of the 500 names (default), or • Weight by volume, market-cap, etc. 4. Practicalities • Include transaction costs or slippage? • Accept daily turnover of 100% (portfolio replaced every day)? • Any liquidity filters beyond “top-500 by volume”?