SK Hynix plunged 15% in Asia after a Korean brokerage's weak profit estimate, dragging the Kospi down 9% and triggering a trading halt. Micron, SanDisk, and Western Digital each fell about 6% in sympathy that same day. Separately, Micron dropped 13.3% on a different date this month tied to a Korean regulator's ETF-risk warning. Micron remains up over 260% year-to-date.
Sources: CNBC, Yahoo Finance, 24/7 Wall St., Bloomberg