https://www.siliconvalley.com/2021/02/01/teslas-dirty-little-secret-its-net-profit-doesnt-come-from-selling-cars/

Tesla posted its first full year of net income in 2020 — but not because of sales to its customers.

Eleven states require automakers sell a certain percentage of zero-emissions vehicles by 2025. If they can’t, the automakers have to buy regulatory credits from another automaker that meets those requirements — such as Tesla, which exclusively sells electric cars.