I'm a little late for this trade, but I feel it's not too too late.
THis is the classic setup - you can see the recent high was 21 and the recent low is 19. Then price action bounced back up to hit 20 - the midway mark - If I had looked at this chart yesterday, I would have put a Sell Order in at 20 and I'd be in good shape already.
Anyway, I put in a Sell ORder for 19.5. Obviously if price action continues to rise this week and it hits 20 again, I will move my Sell Order up to take advatage and sell at 20.