Top Premarket Gainers

07:12 AM EDT, 09/29/2026 (MT Newswires) -- Summit Therapeutics (SMMT) shares were up more than 23% pre-bell Tuesday after AstraZeneca (AZN) agreed to invest $2 billion in convertible preferred shares in Summit, along with a nonbinding clinical collaboration focused on ivonescimab and sonesitatug vedotin. Navitas Semiconductor (NVTS) stock was 12% higher after the company said late Monday it was awarded the Accelerated, Large-Area, 10 kV SiC IGBT program to develop next-generation 10-kilovolt silicon carbide power semiconductor technology. Q32 Bio (QTTB) shares were up 9% after Jefferies initiated the company's coverage at buy with a $29 price target. Deep Fission (FISN) stock was 8.7% higher, partially reversing the 13% loss at Monday's close. Armada Acquisition Corp. II (XRPN) shares were up over 8% after a marginal retreat at the prior close.