Watching a certain coin suddenly surge, I hesitated for a moment and then pressed the buy button. The result? Even though it showed a price of 100 yuan, the transaction actually went through at 102 yuan. This happens every day on exchanges, and many people still don’t know why.

Basically, it’s because you used a market order. After opening the exchange app, you instinctively perform a series of actions without really checking what the order book looks like, and just sweep in to buy. In fact, even pausing for just 1 second to look at the depth chart can make a completely different outcome.

Exchanges actually have two types of players, with vastly different treatment. One type places limit orders, we call them "order posters"—they actively add orders to the order book, effectively providing liquidity to the market. Exchanges especially favor these people, offering lower fees, and sometimes even paying them to trade. The other type uses market orders, "order takers"—they see a suitable price and directly eat up the orders posted by others. Although this method is faster, it essentially consumes liquidity, so their fees are often higher.

If you’re doing short-term trading every day and always rely on market orders, you’re basically giving a large chunk of your profits to the exchange as fees. If you have enough time, developing the habit of using limit orders can really save you a lot. It’s not about rushing for speed; using market orders at critical moments is perfectly fine— but in daily operations, if you’re not in a hurry, giving a little patience to the order book can make a noticeable difference in your account’s performance by the end of the month.