Interactive Brokers - Bitcoin
https://www.interactivebrokers.com/en/index.php?f=25379
On this page there is a link to a "knowledge base" article
https://ibkr.info/article/3049
"Due to the extreme volatility of cryptocurrencies, clients will be unable to assume a short position including as part of a spread. The only time a short order will be allowed will be in the case of a roll trade that results in a long position. In addition, market orders will not be accepted."
.
https://www.interactivebrokers.com/en/index.php?f=25379
On this page there is a link to a "knowledge base" article
https://ibkr.info/article/3049
"Due to the extreme volatility of cryptocurrencies, clients will be unable to assume a short position including as part of a spread. The only time a short order will be allowed will be in the case of a roll trade that results in a long position. In addition, market orders will not be accepted."
.