The magnitude of theta rises exponentially as expiration approaches (exponential time decay) --- ONLY and ONLY --- for ATM options. Theta is more or less flat and decreases to nearly zero prior to expiration rather than increases exponentially. If an option is ATM now, it likely will not be one minute later, and much less likely to remain ATM one month later. Therefore, if you short options, you will have some time decay, but will not have the benefit of EXPONENTIAL time decay on your side (you don't have the benefit of the most powerful weapon; you only have a toy BB gun against your opponent). CBOE, OIC, and many others have taught investors exponential time decay, but I think it is misleading. Any comments?