A short option value is the current marketplace value of all short options in a trading account. Options marked to the last reported price. Market movement may cause bids and offers to be away from the last reported price. Essentially, a short option value is calculating how much cash would flow into the client’s account if the option were hypothetically offset at the current market value. This is another tool traders use to figure out where they stand in the marketplace and how their transactions are currently fairing. However, the long option value is a fluid number, it changes as the market changes, so once again, it is not the “end all be all” number.