Moments after Apple’s Face ID demo face-planted in front of millions of viewers during its annual product unveiling, the company’s stock took a sharp dive.

The drop from around $163 a share to $159 a share — its lowest point on what should have been a banner day — took place right after Craig Federighi, Apple’s senior vp of software engineering, came onstage to demo the new technology but failed to unlock the phone on the first try.