Apple Inc. AAPL, +3.98% and Micron Technology Inc. MU, +4.28% are among the tech stocks enjoying big gains in Tuesday’s session after the U.S. Trade Representative’s office said it would delay tariff increases on certain goods from China. These include laptops, cell phones, and videogames. A new round of tariffs was supposed to take hold on Sept. 1 but tariff increases on these categories will be delayed until Dec. 15, following phone calls between the U.S. and China. Other significant gainers in Tuesday trading include Roku Inc. ROKU, +3.32%, which talked about tariffs on its recent earnings call, Apple suppliers Skyworks Solutions Inc. SWKS, +2.70% and Qorvo Inc. QRVO, +3.17%, and chipmakers Qualcomm Inc. QCOM, +2.65% and Western Digital Corp. WDC, +2.31%.