Jordan Novet / CNBC: Cerebras opens at $350, valuing the chipmaker at $100B+, after raising $5.5B by selling 30M shares at $185, the largest US tech IPO since Uber's debut in 2019  —  Cerebras Systems soared 68% in its Nasdaq debut on Thursday, closing at $311.07 after selling shares at $185, well above the company's expected range.