Then take out a margin loan with them. No one is going to use an account as collateral. Really its not even if someone does take it you can claim it was hacked, get the account back and run off with both the coins and your suppose $200k. If you really need a loan, apply and take out a margin loan, or take your money to a bank and get a secure loan. If you dont have valid collateral that is 120% of what youre seeking, you should go on and just close this thread.