      Because the stakes are often very high in these contracts, sizeableintraday gains and losses can occur as these contracts approach expiration.For options traders, the optimal price of the stock at expiration willequal the strike price of the underlying option contract that they are mostheavily concentrated in. Depending upon the size of the position that anoptions trader has, it is sometimes beneficial to try to move the price ofthe stock to the desired strike price by buying or selling large quantitiesof the stock. Because there are different strike prices, and optionstraders have varied positions at each of these strike prices, competitionto move the stock to one strike price or another sometimes ensues. Thiscompetition translates into abnormal trading volume, in conjunction withincreased volatility.