Cerebras CEO Andrew Feldman, front row, second from left, participates in a ribbon-cutting ceremony for the company's data center in Oklahoma City on Sept. 22, 2025.AI chipmaker Cerebras filed to go public exactly a year ago. The company has yet to take the plunge, but has now bought itself more time to stay private.Cerebras said Tuesday that it's raised $1.1 billion in new funding at a valuation of$8.1 billion as it tries to take on Nvidia, the world's most valuable company, in the booming market of artif ...