The rally follows significant instability earlier this week, which was largely precipitated by Samsung Electronics. That firm’s latest earnings report failed to meet aggressive market expectations, leading to a broader retreat in chip stocks. Investors have seized on the SK Hynix demand as a signal that appetite for specialized memory hardware remains robust despite the recent volatility.

Separately, federal regulators are intensifying pressure on the autonomous-vehicle industry. Authorities are demanding that companies overhaul software protocols after identifying a dangerous pattern of driverless cars obstructing or failing to yield to emergency vehicles and first responders.