I’ll calculate the expected move in JPM once the stock enters its pre-earnings run-up. I’m guestimating over a 5 day period, about $5, which is about a 7% move.
If it can move 4% on the news, good/bad, then over the next 4 trading days it only needs to move 3% in the same direction, to give the estimated move [if that is actually $5]
Of course if there is a significant earnings surprise, or guidance, then a 20% move is not unheard of. FB in the last earnings cycle is one example. Contrary to the usual earnings strategy, an earnings surprise would be a great thing if it were to happen.