Here are some of the biggest U.S. stock movers today: Nvidia (NASDAQ:NVDA) stock rose 2.6% after the Financial Times reported that U.K.-based chip designer Arm is in negotiations with the U.S. chipmaker for it to be an anchor investor in Arm's planned initial public offering. Illumina (NASDAQ:ILMN) stock rose 2.8% after EU regulators hit the genetic sequencing equipment maker with a record €432 million (€1 = $1.1023) fine for closing its acquisition of cancer test developer Grail without first securing regulatory approval.