CoreWeave, an artificial intelligence startup, saw a 17% increase in its shares to $43.50 on the third day of trading, surpassing the initial public offering price of $40. The stock, backed by Nvidia, began trading at $39 on Friday, giving the company a valuation of $23 billion. Nvidia supported CoreWeave's IPO with a $250-million order as part of the $1.5 billion raised. CoreWeave, based in Livingston, New Jersey, offers access to data centers and high-powered Nvidia chips, which are in high demand for developing AI applications.