economic bubble

An economic bubble (also called a speculative bubble, asset bubble, or simply financial bubble) is a period when current asset prices greatly exceed their intrinsic valuation, being the valuation that the underlying long-term fundamentals justify. Bubbles can be caused by overly optimistic projections about the scale and sustainability of growth (e.g. dot-com bubble), and/or by the belief that intrinsic valuation is no longer relevant when making an investment (e.g. Tulip mania). They have appeared in most asset classes, including stocks (e.g. Roaring Twenties), commodities (e.g. Uranium bubble), real estate (e.g. 2000s US housing bubble), and even esoteric assets (e.g. Cryptocurrency bubble). Bubbles usually form as a result of either excess liquidity in markets, and/or changed investor psychology. Large multi-asset bubbles (e.g. 1980s Japanese asset bubble and the 2020–21 Everything bubble), are attributed to central banking liquidity (e.g. overuse of the Fed put).

In the early stages of a bubble, many investors do not recognise the bubble for what it is, often thinking that the increase in asset prices is justified. Therefore, bubbles are often conclusively identified only in retrospect, after the bubble has already "popped" (or "burst") and prices have crashed. The bursting of a bubble can lead to significant financial losses and economic disruption.