Snowflake (SNOW): The cloud-storage company reported a narrower quarterly loss, saying AI drove its business. Its stock surged more than 20% ahead of the bell.

Broadcom (AVGO): The company was bullish about demand for its custom chips over the next two years; shares slipped premarket.

Hewlett Packard Enterprise (HPE): The company's results beat analyst expectations, helped by AI demand. It also lifted its long-term goals; alas, this wasn't enough to boost its shares, which fell around 4% ahead of the bell.

Impala Platinum (ZA:IMP): Higher precious-metal prices gave the South African miner's earnings a boost; its shares climbed.

Ultragenyx Pharmaceutical (RARE): The pharma company said a drug in its pipeline failed to meet its primary endpoint in a late-stage trial; its stock plunged about 45% ahead of the bell.