A MARTINEZ, HOST:

Good morning. I'm A Martinez. A brother and sister in San Francisco used to run a lemonade stand every summer. Now they mine cryptocurrency and earn tens of thousands of dollars every month. As 14-year-old Ishaan Thakur told The Dallas Morning News, most kids like to play games on their computer. We like to build them. He and his little sister, Aanya, have dozens of computers able to make billions of calculations every second, and they say that they're saving up for med school. It's MORNING EDITION. Transcript provided by NPR, Copyright NPR.

NPR transcripts are created on a rush deadline by an NPR contractor. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.