Moody’s Plunges 1.7% as $490M Surge Propels It to 261st Busiest U.S. Stock

On October 10, 2025, Moody’s (MCO) closed at a 1.70% decline, with a trading volume of $0.49 billion, reflecting a 53.93% surge from the previous day. The stock ranked 261st in terms of trading activity among listed equities. Analysts noted that the volume spike likely stemmed from position adjustments ahead of regulatory reporting deadlines, though no immediate catalysts for the price drop were identified in the broader market context.

Recent market activity suggests heightened sensitivity to macroeconomic signals, as investors recalibrated portfolios amid shifting inflation expectations. While Moody’s core credit ratings business remains resilient, sector-specific volatility has persisted due to divergent performance across financial indices. The company’s exposure to global debt markets has historically amplified its equity price swings during periods of systemic uncertainty.

It sounds like you would like to simulate a daily-rebalanced portfolio that, every trading day from 2022-01-01 onward: (1) Sorts all tradable stocks by that day’s dollar trading volume. (2) Buys (equal-weights) the top 500 names at that close. (3) Liquidates the position at the next day’s close. To run an accurate back-test we need to pin down a few practical details that aren’t fully specified yet: Market universe – Should we use only U.S. listed common stocks (NYSE + NASDAQ), or a broader global universe? Survivorship bias / delistings – OK to rely on today’s live symbol list, or do you want a survivorship-bias-free universe that includes delisted names? Corporate-action adjustment – Split- and dividend-adjusted prices (total-return series) are standard; confirm that is acceptable. Weighting scheme – Equal-weight each of the 500 names (1/500 each), or volume-weighted? Transaction costs – Should we assume zero commission/slippage, or include an estimate? Benchmark – Any particular benchmark you’d like to compare the strategy against (e.g., SPY)? Once we have these items nailed down I can generate the data retrieval plan and kick off the automated back-test.