Shares of technology companies fell as concerns lingered about the sustainability of a rally in the chip sub sector.

South Korean memory-chip maker SK Hynix plans to buy back and cancel more than $28 billion of its shares over the next three months, accelerating its shareholder-return program in an effort to restore investor confidence after a volatile period.

Shares of U.S. chip maker Analog Devices were more or less flat despite a boost to quarterly sales from data-center demand.

The PHLX "SOX" Semiconductor Sector index is hovering around bear-market territory, roughly 20% below recent record highs.

Shares of bitcoin-related companies rose ahead of a meeting of cryptocurrency industry leaders and President Donald Trump. Strategy, one of the largest corporate buyers of bitcoin, surged by roughly 10%.

OpenAI promised not to retain data from businesses using its artificial-intelligence models while increasing the safety of its products, a bid to snatch customers from rival Anthropic who are upset the maker of Claude is keeping their information.

OpenAI's relatively muted 18% sequential revenue growth in the second quarter had triggered some investor fears that it was falling behind its main rival.