In recent years a new-disquieting-form of disruptive innovation has emerged, one that beats incumbents on both price and quality right from the start and quickly sweeps through every customer segment. This kind of "big bang” disruption can devastate entire product lines virtually overnight. Look at the effect that free navigation apps, preloaded on smartphones, had on the market for devices made by TomTom, Garmin, and Magellan. Big-bang disruptions often come out of the blue from people who aren't your traditional competitors. Frequently, they're developed by inventors who are just doing low-cost experiments with existing technologies to see what new products they can dream up. Once launched, these innovations don't adhere to conventional strategic paths or normal patterns of market adoption. That makes them incredibly hard to combat. Though technology- and information-intensive firms are most vulnerable to big bangs, mature industries face this threat, too. Credit cards, automobiles, and education, for instance, are all experiencing early warning signs. But in every industry, big-bang disruption will be keeping executives in a cold sweat for a long time to come. This article, which originally appeared in Harvard Business Review, offers some strategic principles to help businesses survive big bangs.