If you bought the stock in a cash account and paid for it in full, you'll earn a 50 percent return on your investment. But if you bought the stock on margin – paying $25 in cash and borrowing $25 from your broker – you'll earn a 100 percent return on the money you invested. Of course, you'll still owe your firm $25 plus interest. Understanding how a brokerage settles trades can make the difference in your decision to use a margin account or stick with a cash account. When trading stocks , bonds, options, or Treasury securities , the so-called regular-way trade settlement process requires you to deliver the cash if you are buying, or asset if you are selling, by the end of a certain number of days following the trade date itself. The securities in your margin account may be lent out to another party, or used as collateral by the brokerage firm at any time without notice or compensation to you when there is a debt balance (or negative balance) on the account where you have accessed the margin funds. If the account is in a credit state,