Quantum-computing stocks were falling again Friday after slumping in the previous session as investors were left disappointed by a Nvidia event aimed at celebrating the technology.The artificial-intelligence chip maker’s Quantum Day was lacking in major announcements and the formerly highflying stocks tumbled.

The chipmaker NVIDIA held its annual conference in Silicon Valley this week. Among the major announcements: it chose Boston to be the site of its first-ever research center for quantum computing, opening later this year.