I just noticed that many people still don’t truly understand what an asset bubble is—and why it matters for investors.

Asset bubbles happen when prices rise above the asset’s real value—whether it’s stocks, real estate, crypto, etc. The problem is speculative behavior and investors’ excessive confidence. Everyone rushes in because they see others making profits—not because they truly understand the fundamentals of the asset.

Let’s look at examples from history. The 2008 subprime crisis is a very good case study. Banks began approving mortgage loans for people who couldn’t afford to repay. The real estate market surged rapidly. Investors flocked to buy houses for speculation. Financial institutions created complex financial instruments—until the borrowers started defaulting. Everything collapsed immediately, and bad debt around the world surged to 15,000 million dollars.

As for Thailand’s 1997 Tom Yum Goong crisis, it was caused by a similar pattern. Interest rates were extremely high because foreign capital flowed in. The real estate market boomed and a bubble formed. When the baht was devalued, debts denominated in foreign currency rose sharply. The bubble burst, real estate prices fell, and investors who had borrowed heavily were unable to repay their loans.

There are many types of bubbles, not just real estate. We have stock market bubbles, which occur when stock prices rise to irrational levels. There are credit bubbles, when lending expands rapidly. And there are commodity bubbles—such as gold and oil—where prices rise in an uncontrollable way.

Why do bubbles form? Most of the time, they start with good economic conditions—low interest rates, new technology, or the discovery of new investment opportunities. But when prices begin to soar, human psychology takes over. Fear of missing out, herd mentality, and overconfidence set in. Everyone believes they will definitely make profits and can exit the market before it bursts.

Bubbles inflate through five stages. First is displacement—when something new and exciting appears. Second, prices start climbing as investors pour in. Third, excitement builds because everyone can see the profits being made. Fourth, some investors begin selling to lock in gains. Fifth is panic—when everyone realizes the bubble is running out of air, a wave of panic-driven selling occurs, and prices drop rapidly.

So what should we do? First of all, you need to truly check your own objectives. Are you investing because you understand the asset, or because you’re afraid of missing out? If it’s the latter, you may be contributing to the bubble’s expansion.

The way to protect yourself is to diversify your portfolio. Don’t put all your money into a single type of asset. Limit speculation when you suspect a bubble is forming. Try dollar-cost averaging—invest small amounts over time. Keep some cash reserves so you can take advantage of opportunities after the bubble bursts. And most importantly, study the market well. Understand the assets you invest in, keep up with information, and do your research before making decisions.

In short, bubbles occur when prices rise far above their true value due to speculative behavior and human psychology. They keep happening over and over throughout history, and their impacts can be severe. That’s why being prepared, diversifying risk, and doing in-depth research are essential—no matter what assets you invest in.