## The "Doi" Phenomenon in the Stock Market - Mistakes Investors Should Avoid

If you are new to investing, the term **"Doi"** might sound like a new slang, but its meaning is an important warning that all investors should be aware of.

### What is Doi and what are the real causes

**Doi** occurs when investors make decisions to invest in assets such as (stocks, funds, or crypto) expecting prices to rise, but the opposite happens — prices drop rapidly and sharply. At this point, instead of accepting the loss and selling, many investors choose to "hold tight" and wait for the price to bounce back. The result is an increased average cost per unit and deeper losses.

The main causes of Doi are threefold:

**First: Buying after a sudden price surge** When a stock jumps from 5 baht to 6, 7, or 10 baht in a short period, the market atmosphere and emotions tend to attract many investors. People rush to buy at high levels without proper fundamental analysis. When the momentum stops, prices tend to fall just as quickly.

**Second: Believing unclear information** Rumors about major investors entering or unconfirmed good news announcements often create hope among investors to buy in. Often, such news is just a strategy by major shareholders wanting to sell their shares. Once they sell out, the news disappears, trading volume decreases, and retail investors are left holding stocks that no one is interested in.

**Third: Buying good stocks at too high a price** Sometimes, after thorough fundamental analysis, you find stocks with strong growth rates, good financial status, and reasonable P/E ratios. But the problem is that you buy too late. After the price has already risen, negative news causes the price to fall sharply.

### Effective ways to prevent Doi

**1. Strictly follow the Stop Loss rule**

Stop Loss is setting a signal point to "exit the position" without debate. For example: if you buy a stock at 20 baht and decide to accept a 5% loss (which is 1 baht), then set the Stop Loss at 19 baht. When the price hits this level, sell immediately without thinking, "It might go up again." The acceptable percentage depends on each individual's risk tolerance.

**2. Prepare exit points to lock in profits from the start**

For those following a Short-term Trading strategy, have a clear selling plan. For example: if you buy 5,000 shares at 5 baht (for 25,000 baht), plan to sell when the price reaches 5.2 baht. When the price moves according to the plan, execute the sale immediately. Small, consistent profits are better than waiting for large gains with higher risk (Scalping) often yields better results.

**3. Never invest in what you do not understand**

Before buying any stock, ask yourself seriously: What does this business do? Which industry is it in? Does it have good human resources? How have its operations performed over the past 3-5 years? Is the current price reasonable? Investing based on hype and emotion often leads to long-term regret.

**4. Use dollar-cost averaging if you believe in the fundamentals**

If you have studied thoroughly and are confident that the stock has solid fundamentals, but the price has dropped significantly, you can "buy more." For example: buy 1,000 units at 1 baht (invest 1,000 baht), then when the price drops to 0.5 baht, buy an additional 2,000 units (invest another 1,000 baht). Now, you hold 3,000 units with a total investment of 2,000 baht, reducing the average cost to 0.67 baht per unit. When the price recovers, profit-taking becomes easier.

### Things to remember

**Doi** is not something that happens by chance. It results from decisions made without proper foresight, emotional investing, and refusal to cut losses. Final advice: if you are afraid of Doi, it means you understand the risks. The next step is to invest with discipline and a clear plan. Because falling into Doi from a Doi situation can always happen, as long as you have a good plan.