This tool for TOS makes one-leg options trades super easy by displaying lots of useful options information directly on the underlying stock’s chart. It displays the strike price and breakeven price on the price chart, and tells you the current price of the option, the price change of the contract, and the number of days until expiration. In addition, it will calculate the theoretical profit or loss at different levels, taking into account the underlying price change, number of days in the trade, and change in implied volatility. You are able to change each of these parameters to see what the profit or loss would be under many different scenarios. You can also choose the expiration date, whether the option is a call or a put, and whether the trade is long or short. It automatically picks the at-the-money strike price for you, but you can shift the strike price upward or downward.