O que é Implied move?

The implied move of a scheduled event is the expected absolute return on the event day that option prices imply. Under a normal event return with the event variance $E$ extracted from the term structure it is $\sqrt{2/\pi}\,\sqrt{E}$. Traders often approximate it by the price of the at-the-money straddle expiring just after the event, as a share of the stock price.