Seagate (STX) Stock After Hours Today: What Happened After the Bell on Dec. 19, 2025 — and What to Watch Before the Next Market Open
Seagate Technology Holdings plc ended Friday’s regular session higher and held onto gains in after-hours trading, keeping the data-storage name in focus as investors head into a weekend packed with positioning effects — and a major index catalyst set for the next U.S. session. Public+2TradingView+2 One important calendar note up front: Dec. 19, 2025 is a Friday, so U.S. stock markets are closed on Saturday, Dec. 20. The next regular market open is Monday, Dec. 22, 2025 — and that date matters for STX because of a scheduled Nasdaq-100 index change becoming effective prior to that open. Nasdaq