Who knows the reason only for themselves. But I think they are worried that the crypto market will not go up again. They don't want to be caught in a worse situation. Maybe they have been waiting for a few months when the market doesn't recover. So they take steps to sell coins even though they lose.
That is the possible scenario. Losing faith in cryptocurrency and even at a loss, they are selling it. Continues FUD news and uncertainty in government policies adds to this sell off. I hope this problem will be solved and all stakeholders should iron out this issues.