Short term fiscal investing can be a challenging business. Short-term positions are those that are held for less than a month or so. In stock investing, being short on an advantage means holding it in a costly way so you will reap maximum advantage once the market falls. This is the reverse of an"over" position, where you will benefit when the market rises. Both are considered"call" positions, which means that your gain is tied to the motion of the cost once the investment is made.