** Shares of U.S. chipmakers fall in premarket trading, tracking weakness in the sector globally

** Over the weekend, Tehran said it had closed the Strait of Hormuz again following renewed fighting with the U.S., which sent oil prices higher and dented risk appetite

** U.S.-listed shares of SK Hynix SKHY.O drop 9% as investors book profits after an over 12% surge in their Nasdaq debut on Friday

** Memory chipmakers Micron Technology MU.O falls 5.2%, Western Digital WDC.O and Seagate Technology STX.O lose 5.6% and 4% respectively, while Sandisk SNDK.O falls 6.5%

** Analysts expect the upcoming earnings season to be a test for stretched valuations in the sector, which could sustain or temper the eye-popping rally this year

** Shares of AI chipmaker Nvidia NVDA.O fall 1.3%

** Networking chipmakers Broadcom AVGO.O and Marvell Technology MRVL.O slip 1.7% and 2.5% respectively, while smartphone chipmaker Qualcomm QCOM.O loses 2.2%

** Advanced Micro Devices AMD.O and Intel INTC.O, which make chips for personal computers, servers and AI chips, decline 2.6% each

** U.S.-listed shares of contract chipmaker Taiwan Semiconductor Manufacturing TSM.N were little changed, as it posted a record second-quarter revenue, cushioning the blow

** Shares of chip-making equipment companies like Applied Materials AMAT.O, Lam Research LRCX.O and KLA Corp KLAC.O also fall over 3% each

** The iShares Semiconductor ETF SOXX.O was down 2.6%, while the VanEck Semiconductor ETF SMH.O was off 2%

** The Philadelphia Semiconductor Index .SOX has added over 83% YTD as of last close vs a 10% gain in the benchmark S&P 500 .SPX