Recently, many beginners have been asking what a limit-up is, so I decided to clarify this part.

Actually, limit-up and limit-down are the "ceiling" and "floor" in the stock market. For example, in the Taiwan stock market, the daily price change limit cannot exceed 10% of the previous day's closing price. In other words, if TSMC closed at 600 yuan yesterday, today the highest it can go is 660, and the lowest is 540. Once the stock price hits this limit, trading is frozen, which is the state of limit-up or limit-down.

How to tell if a stock has hit the limit-up? Very simple, just look at the candlestick chart. The limit-up stock's line will turn into a straight line, unmoving. On Taiwan stock software, limit-up is marked with a red background, and limit-down with a green background. More obviously, look at the order book—at limit-up, buy orders pile up, and sell orders are almost nonexistent because there are too many buyers. Conversely, at limit-down, sell orders pile up, and buy orders are few.

Many people ask if they can still trade when a stock hits the limit-up. Yes, they can. Limit-up does not lock trading; you can still place orders. But there's a trap—your buy orders may not get filled because a large number of buy orders are already queued at the limit-up price, waiting to be executed. Conversely, if you sell, it can be executed immediately because many want to buy. The logic is reversed at limit-down: buy orders can be filled instantly, but sell orders may not.

However, the gameplay in US and Hong Kong stocks is different. The US stock market has no limit-up restrictions but has a "circuit breaker" mechanism—if the S&P 500 drops 7%, trading pauses for 15 minutes; at 13% drop, another 15-minute halt; at 20%, the market closes for the day. Individual stocks also have circuit breakers, such as a 5% move within 15 seconds pausing trading for 5 minutes. Hong Kong stocks also do not have limit-up boards; they rely on market regulation mechanisms to maintain stability.

When encountering a limit-up stock, never blindly chase it. You need to understand the reason behind the limit-up—whether it's genuine positive news or just market sentiment. If the company's fundamentals are solid and the movement is just short-term volatility, you can consider holding or small-scale building positions. If the limit-up is due to real positive news, also assess whether that news can support further gains. Often, waiting and observing is the smartest choice.

Another approach is, when a stock hits the limit-up, you can buy related stocks or stocks in the same sector. For example, if TSMC hits the limit-up, other semiconductor stocks usually follow suit.

If you really can't buy the stock you want to trade, consider Contracts for Difference (CFD). CFD is a contract product that tracks stock prices, similar to trading stocks but with lower barriers—small capital can control large positions. Plus, CFDs can be traded 24/7, not limited by stock market hours. You can go long (buy) or short (sell), making trading more flexible.

In summary, limit-up and limit-down are part of the market's stability mechanisms. When encountering these situations, staying rational is most important—don't let emotions drive you into chasing highs or selling lows. Analyzing the underlying reasons will help you make better trading decisions.