Arm Holdings up after third-quarter revenue forecast tops expectations

** U.S.-listed shares of Arm Holdings ARM, ARM rise 2.1% to $163.18 after the bell

** ARM forecasts Q3 revenue of $1.23 billion at the midpoint of its guidance, above analysts' estimates of $1.1 billion, according to data compiled by LSEG

** Posts Q2 revenue of $1.14 billion, up 34%, beating estimates of $1.06 billion

** Q2 royalty revenue jumps 21% to $620 million; licensing revenue soars 56% to $515 million

** Stock had risen ~30% YTD