On Thursday after the market close, Nvidia said its first quarter revenue jumped 66% to $3.2 billion, more than analysts expected, and adjusted net income per share more than doubled to $2.05, also beating the average estimate. But looking deeper, Nvidia said its sales to datacenters, which largely use the graphics chips for machine learning and artificial intelligence apps, reached only $701 million, less than expected. And the company disclosed that volatile sales to customers who mine digital currencies like Ethereum totaled $289 million.

Some investors fear that with digital currency prices declining, mining activity–actually running massively complex computing calculations–could fall off. Also some smaller Asian chipmakers are expected to bring out more efficient and specialized mining chips soon that could grab some of the business going to Nvidia and its rival, Advanced Micro Devices (AMD). Intel (INTC) doesn’t currently make the kind of graphics chips used in cryptocurrency mining.

“Looking into Q2, we expect crypto-specific revenue to be about one-third of its Q1 level,” CFO Colette Kress said on a call with analysts.

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On Friday, Nvidia (NVDA) shares were down 1% to $257.71 in midday trading.

“Cryptocurrency mining continues to inject noise into an overall very strong growth story,” Morgan Stanley analyst Joe Moore wrote in a report on Friday, saying demand from miners had accounted for about half of the surprise extra revenue Nvidia reported beyond what analysts expected. But the company’s strong growth in other areas should overcome any decline in that business, Moore argued, as he raised his price target on the stock to $273 from $258.

Analyst Stacy Rasgon at Bernstein Research suggested investors should stop worrying so much about the impact of crypto sales.

“There was very little to nitpick on regarding execution and as numbers continue their inexorable march higher we continue to believe the story has legs,” he wrote.