** Shares of chipmaker Marvell Technology MRVL.O down 7.8% at $56.46 before the bell after investor day postponement

** Wilmington, Delaware-headquartered firm late Tues said it's postponing previously scheduled investor day event, citing an uncertain macroeconomic environment

** Co, which is moving the event to a future date in 2026 from June 10, also said it would host a Jun 17 webinar focused on opportunity of custom silicon tech for AI infrastructure

** It maintained midpoint of Q1 rev guidance, and narrowed forecasted range. Co now sees rev of about $1.875 bln, within a range of plus or minus 2%

** Global chip firms have been pummeled by U.S. President Donald Trump's tariff salvos, clouding the outlook for the industry

** Nvidia NVDA.O has warned of a $5.5 bln hit after Washington restricted exports of its AI processor tailored for China, while Dutch chip-making tools giant ASML raised doubts about its outlook

** Through Tues close, MRVL shares have fallen ~45% YTD vs Philadelphia Semiconductor index's .SOX 13% decline

** Of 39 analysts covering MRVL, 36 rate stock "strong buy" or "buy", rest rate "hold"; median PT of $100 down from $110 a month ago and from $130 on Feb 7 - LSEG data

(Lance Tupper is a Reuters market analyst. The views expressed are his own)

((lance.tupper@tr.com 1-646-279-6380))