Dexcom Slides 0.84 as FDA Review and 374th Volume Rank Highlight $12B CGM Sector Rivalry

On September 15, 2025, , ranking 374th in market activity. .

Recent developments highlight regulatory scrutiny as the FDA initiated a review of Dexcom’s G7 continuous glucose monitoring system. This follows routine post-market evaluations but has triggered investor caution. Analysts note the review does not indicate product safety concerns but reflects standard oversight procedures for medical device innovators.

Market participants are also monitoring Dexcom’s competitive positioning as major rivals expand their portfolios. While no direct product announcements were disclosed, .

To run this back-test accurately I need to refine a few practical details that aren’t fully specified yet: 1. Market universe • Do we look at all U.S. listed common stocks (NYSE / NASDAQ / AMEX), or a different universe? 2. Ranking & execution timing • Should the “top-500 by daily trading volume” list be formed with same-day data and the portfolio bought at that day’s close, or do you prefer to form the list after the close and buy at the next day’s open (which is more realistic and avoids look-ahead bias)? 3. Price series for measuring returns • Use daily close-to-close returns, or open-to-close (buy next-day open, sell same-day close), or another convention? 4. Weighting & rebalancing • Equal weight on each of the 500 names and rebalanced every trading day (holding period strictly one day)? 5. Transaction costs • Should we include any trading cost assumptions (e.g., 1 bp per side), or ignore them for this first run?