MMC's $430M Volume Ranks 273rd as Shares Dip 0.65% Amid Regulatory Scrutiny and Restructuring

On September 16, 2025, , ranking 273rd in market activity for the day, .

The insurer’s performance was influenced by regulatory scrutiny over evolving risk management frameworks. Analysts noted that ongoing evaluations of its risk-adjusted capital models have introduced short-term volatility, particularly amid shifting market expectations for insurance sector resilience in Q4.

Internal restructuring efforts also played a role, as Marsh announced phased cost optimization initiatives targeting operational efficiency. While the moves align with long-term strategic goals, investors remained cautious about near-term earnings compression, reflecting mixed sentiment in volume patterns.

To set up this back-test precisely, I need to pin down a few implementation details: Trading universe—scan every U.S.-listed common share (NYSE + Nasdaq + AMEX) or a different market/universe? Ranking and entry price—rank by the current day’s trading volume, then buy at that day’s close (close-to-close return), or buy at next day’s open? —equal-weight the 500 names each day, or weight by something else (e.g., volume-weighted, market-cap-weighted)? Costs & slippage—include estimated commission/slippage, or assume frictionless execution? Cash management—if not all capital is deployed every day (e.g., odd lot rounding), park the rest in cash at 0% return—is that acceptable? If you’re happy with the following defaults, let me know and I can proceed immediately: Universe: all NYSE, Nasdaq, and AMEX common stocks (ex-ETFs, ex-OTC). Entry: buy at the close on the day a stock ranks in the top-500 by volume; exit at the next day’s close. Weights: equal-weight the 500 stocks each day. Costs: none (frictionless). Cash: held at 0% if any residual.