Tell them the options were bought on the advice of a psychic reading. Or an Ouija board. Given that people know of the Death Note, they would suspect you to be the holder of the Death Note. Without that suspicion, it's just a massive coincidence.

Alternatively, buy the options as part of a hedge, or as part of a variety of out of the money put options, or as part of any other broad investment strategy. If you get hundred-to-one returns, if it's 5% of your portfolio then you still have five-to-one returns, which is plenty.