I'm not so much interested in leverage but I am interested in ability to short. I do know I could use Kucoin and I believe I could use kraken. But is it legal for US citizens to use leverage or to short Bitcoin? I've recently come across some information that says, apparently starting last year, it became illegal. Does anyone know?

I'm going to check for a support email on both sites and ask them, but I was just curious because I've been trying to find out what exchanges I can short Bitcoin on and I every time I come across one it says that I can't use that exchange. (us location) So I'm wondering is this a nationwide thing or is it an individual exchange thing?