** Philadelphia Semiconductor Index .SOX rises 0.6%, bucking the broader market trend as signs of increasing investments in AI spurred bets of higher demand for chips that support the technology
** Broadly, Meta Platforms META.O drops 13%, weighing on tech peers and pulling the S&P 500 .SPX 1.5% lower after the Instagram parent forecast higher AI expenses and lighter-than-expected revenue
** "Semis are broadly stronger, buoyed by META's capex spend (at least $70 bln over 2 years)" - J.P.Morgan traders'
** AI bellwether Nvidia NVDA.O firms 2%, while Broadcom AVGO.O, Marvell Technology MRVL.O and Lam Research LRCX.O advance between 2.6% and 4%
** Alphabet GOOGL.O and Microsoft MSFT.O, slated to report quarterly results after markets close, said earlier this year they expected AI costs to rise
** Semiconductor-testing equipment maker Teradyne TER.O climbs 6.7% after upbeat forecast
** SOX up 10% YTD on AI boost compared to 5% gain in SPX
(Reporting by Medha Singh)