A margin account with a sweep preference of Money Market Fund will be subject to our general policy, which requires the deposit in cash or collateral on initial transactions of 50 % of the value of the marginable security as prescribed under Regulation T of the Board of Governors of the Federal Reserve System. (capitaloneinvesting.com)
The possible initial transaction costs at TD Ameritrade are $ 9.99 per stock / ETF trade and a maximum of $ 24 per mutual fund trade. (thecollegeinvestor.com)
It should be noted that initial transactions effected in a margin account with FDIC Insured as the sweep preference may be subject to an initial deposit in excess of 50 %, in fact a deposit of 100 % may be required. (capitaloneinvesting.com)