Coherent had gained about 4.2% in the preceding session, then lost roughly 12.7% on September 14. The recovery had supplied no durable support. CoreWeave fell about 6.8%, Micron 5.3%, and semiconductor ETF SMH 4.8%. Optics, compute rental, and memory are different businesses; their prices came under pressure together.
SPY lost only about 0.4% and QQQ 0.8%. Those broad-market moves barely conveyed the scale of the hardware losses. SPY, QQQ, and SMH have different constituents and weights, so other businesses can dilute hardware declines. The smaller index loss does not establish safety across the market.
The shared decline fits a thematic valuation-pressure account. Without positioning or participant evidence, it cannot be called established crowded selling, or the same new operating problem at three companies. The longer AI-demand story did not shield these shares from the day’s losses. Damage inside the theme was visible at the New York close; a systemic conclusion remained unsupported.
Historical backfill: compiled October 4, 2026, with observations limited to the date discussed and US prices through the September 14 New York close. Sources: Yahoo Finance historical prices for COHR, CRWV, MU, SMH, SPY and QQQ, September 10, 11 and 14. Daily moves use the preceding session close. Positioning and valuation mechanisms are possible interpretations, not verified event causes. COHR, CRWV and MU are analysis subjects only, not KSINQ recommendations to buy, sell or hold them. This article presents personal research and opinion for informational purposes only and does not constitute investment advice.