Almost all of the great bottoms in recent history have a retest within a few days or weeks ('74, '87, '98, '00 etc). There are some anomolies like sept 21st that went straight up. But retests wash out the remaining weak holders and they often cut through the previous low ('74, '98 for example) to suck more shorts in. If the VIX gets back into the mid 50's, or if the DOW bounces on key support of 7400, it's a high probability trade on the long side. August calls will look great.