Hypothetical case: let's say I open a margin account with a broker and transfer exactly 25K into that account. The next day I use that 25K 4 times to buy and sell shares with a total profit of let's say $500. In most cases it takes about 1 day for funds to settle. Does that mean the liquidity for that account is actually 0, which means you broke the PDT rule? If so then the PDT rule for margin accounts means you deposit 25K to always have in the account and then you transfer the amount you actually want to trade with.