One drawback of the above ShortLadders and the LongStraddle is that they work best if DTE is extremly short, like <= 5. This is impractical b/c usually the exact date of the expected event is not known in advance (exception: the quarterly Earnings Release (ER) dates).
So, be cautious when using them. Always check the PnL diagram first for the percent distance of the B/E points.
For such Event Trading (FDA decisions etc), they should not be more than about 40% distant from the current stock price; the less the better..
