The BTC of the dual currency financial product $BTC was still sold off at its own price of 91000. I don't know if there's a chance to buy it back? Or what to do if I'm worried about not having the opportunity, I'll just treat it as mining, putting the previous interest and the principal of 750 dollars together, and continuing the dual currency experiment.

The contract risk is too high, and spot trading should be held for the long term, then doing some dual currency is also a good choice. The only concern is that encountering a one-sided market like these past two days can be quite uncomfortable. If it goes below 91000 for spot buying, the rest will wait until June 13 when the price falls below 91000.