The Option seller receives a premium from the Option buyer at the time of the option transaction. The Option seller has the obligation to sell to the Option buyer (call) or purchase for the option buyer (put) the underlying. For undertaking this obligation, the Option seller receives a premium at the time of the opening of the Option transaction. This premium is his to keep if the Option is not exercised or sold. This Option premium is the maximum amount of profit that the Option seller can make, and the Option seller always has unlimited risk if the market moves against his position.