TSMC is trading at $418.64, -3.07%, amid a sharp semiconductor selloff. - The semiconductor sector is down 3.64% pre-market. - Lam Research shares fell about 8% overnight after it cited supply constraints delaying shipments and warned of a lower China revenue contribution in the December quarter. - Broader risk-off sentiment is weighing on technology stocks. Moody’s Aa2 upgrade is positive company news but does not explain the decline.