If you've made a windfall profit, take it and run. If you're leveraged up to the pits and speculating on big gains, bail. If you're within a few years of retirement with most of your net worth in four walls, suck it out. If you cannot afford to see your equity peeled back by a third or more, and stay that way for years, then retreat. If you listened to Mom and bought a condo with diddly down, get out.