Dexcom Plummets 1.80 as Trading Volume Surges 94.49 to 490M Ranking 262nd in Market Activity

Dexcom (DXCM) closed 10/1/2025 with a 1.80% decline, despite a 94.49% surge in trading volume to $490 million, ranking 262nd in market activity. The stock's performance followed a mixed earnings report showing improved revenue but below-forecast guidance for Q4 2025, raising questions about near-term growth sustainability.

Recent regulatory developments cast uncertainty over the company's expansion plans. The FDA delayed approval of Dexcom's next-generation continuous glucose monitoring system by six months, citing additional data requirements. Analysts noted this could pressure Q4 shipments as competitors like Abbott and Medtronic strengthen their market positions. Meanwhile, a key partnership with a major health insurance provider remained unresolved, with negotiations reportedly stalled over pricing terms.

To run this back-test accurately I’ll need to clarify a few practical details: 1. Stock universe • Should we use all U.S. common stocks (≈ 3 000+ names) or some other universe (e.g., only S&P 500 constituents)? 2. Portfolio construction • Do you want the 500 names equally weighted each day, or weighted by another scheme (e.g., proportional to volume)? 3. Execution price assumptions • Buy at that day’s close and sell at the next day’s close? (This is the most common one-day-hold convention.) 4. Transaction costs/slippage • Should we ignore them or apply a specific assumption (e.g., 0.02 % each side)? Once I have those details I can generate the entry/exit signals and run the back-test from 2022-01-01 to today.