I've noticed that many newcomers to crypto have no idea how prices actually work on exchanges. I think it's worth understanding this together.

It all starts with the basics: when you want to buy or sell an asset, a price difference arises between you and the other party in the trade. This is the bid-ask spread—the gap between the highest price a buyer is willing to pay and the lowest price a seller is asking. It sounds boring, but it directly affects your money.

That's why it's important. On liquid markets like Bitcoin, this spread is minimal—literally a few cents. But if you're trading a less-known coin, the spread can be huge. The simple reason: many people want to trade Bitcoin, so competition among market makers narrows the gap. When an asset is traded infrequently, no one competes, and the spread widens.

Market makers are essentially people who profit from this spread. They buy and sell simultaneously, earning a profit from the difference. Imagine: a market maker buys BNB at $350 and immediately sells it at $351. Doing this thousands of times a day, even a one-dollar spread becomes a serious sum.

But there's another thing that can ruin your day—slippage. This is when you place a large order, and it gets filled at a price different from what you expected. Why does this happen? Because your volume isn't enough to match the best prices in the order book, and the order starts "sliding" up the order book, taking the next available prices.

This is especially painful on volatile or low-liquidity altcoins. Slippage can be 10% or more of the expected price. I've seen people lose serious money because they didn't account for this factor.

To understand how much the spread affects an asset, you need to measure it in percentage terms. The simple formula: (seller's price – buyer's price) divided by seller's price, multiplied by 100. It sounds complicated, but in practice, it's a quick estimate. Bitcoin might have a $3 spread, which is just 0.0083% of the price—a very narrow spread. A less liquid asset with a $6 difference could be 0.66%—that's already noticeable.

What can you do to minimize losses? Here are some proven methods. First—don't put your entire volume in at once. Break a large order into smaller parts and watch the order book. Second—if you're trading on a decentralized exchange, remember about gas fees—they can sometimes eat up all your savings. Third—use limit orders instead of market orders if you can wait. A limit order guarantees you the price you want or better.

Some platforms also have a slippage tolerance feature—this helps, but you need to be careful. Set the tolerance too low, and your order might not execute at all. Set it too high, and you risk a bot jumping ahead of you and reselling the asset at a higher price.

In the end, when you trade, remember: bid-ask spread and slippage are not enemies—they are just market realities. They are barely noticeable on small orders, but when you start working with serious volumes, they become critical factors. Ignoring these things means leaving money on the table. This is especially important if you're diving into DeFi and decentralized exchanges. Without understanding these basics, you can easily lose more than you planned.