DexCom is trading 28.25% down at $64.24 after-hours on September 22, 2026, with no confirmed company-specific catalyst. - No confirmed September 22 earnings release, regulatory action or other late-breaking company announcement was identified. - The latest identified corporate news was the September 14 promotion of Jereme Sylvain to COO, before the decline. - Broader trading was mixed: the Nasdaq was up 0.61%, offering no clear explanation for the isolated drop.