
An asset bubble forms when prices rise far beyond what the asset seems worth, driven more by belief and speculation than fundamentals. People buy not for income or cash flow, but because they expect prices to continue climbing.
Bubbles have been around as long as people have speculated with money. From the 17th-century Tulip Mania and the 18th-century South Sea Bubble to the more recent dot‑com boom and the US housing crash that triggered the 2008 financial crisis, the pattern repeats. More recently, cryptocurrencies and meme stocks have shown how fast prices can rise and fall when the fear of missing out takes over.

Rising asset values often encourage investors and companies to borrow against their holdings. If a bubble pops:
When prices plunge, credit dries up, businesses reduce spending, and layoffs can follow. Pension funds lose value, hitting even those who have never bought a single stock. As economist John Maynard Keynes warned, markets can stay irrational longer than you can stay solvent.

Bubbles can continue expanding until confidence breaks. In the late 1990s, US Fed chair Alan Greenspan called this dynamic “irrational exuberance.”
It’s relatively easy to spot the warning signs: hype replaces fundamentals, and new, often inexperienced buyers pile in.
But guessing when a bubble will burst is much more difficult. Sometimes assets can continue rallying for months or even years once the first red flags pop up. When confidence is finally shattered, the unwind can be brutal. During the dot-com crash, the Nasdaq Composite fell nearly 40% in less than two weeks. The decline continued unevenly until bottoming out in October 2002, when the index had lost nearly 80% of its value from its March 2000 peak.