A range of things can happen when an asset bubble finally bursts, as it always does, eventually. Sometimes the effect can be small, causing losses to only a few, and/or short-lived. At other times, it can trigger a stock market crash, and a general economic recession, or even depression. Much depends on how big the bubble is—whether it involves a relatively small or specialized asset class, vs. a significant sector like, say, tech stocks or residential real estate. And, of course, how much investment money is involved. Another factor: to what degree debt is involved in inflating the bubble. A major 2015 research study, "Leveraged Bubbles," examined asset bubbles in 17 countries, dating back to the 1870s. It categorized them into four types, but along two basic lines, based on credit—that is, how funded investments were by financing and borrowing. The study found that the more credit involved, the more damaging the bubble's pop. Debt-fueled equity bubbles led to longer-lived recessions. Even worse were leveraged housing bubbles, like the one that popped in 2006-07, leading to the subprime mortgage crisis that kicked off the Great Recession.