WASHINGTON—Nvidia has agreed to pay $5.5 million to settle a regulatory investigation that found it didn’t adequately reveal the impact of cryptomining on its sales of powerful chips designed for computer gaming.

The Securities and Exchange Commission said Nvidia’s sales of its graphics processing units, or GPUs, were materially boosted in its 2018 fiscal year by consumers who bought them to mine new units of cryptocurrencies. Nvidia kept investors in the dark about that fact over two quarters, depriving shareholders of information they needed to understand its future financial performance, the SEC said Friday.