When trading stocks, people often focus only on return rates—yet it’s common to end up losing money because of fees. Recently, I looked into the fees charged by different securities firms in detail, and the differences turned out to be larger than I expected.

First, let’s整理 what fees are. Fees are the costs you have to pay every time you buy and sell stocks. Depending on the case, you may see different charges added, such as brokerage commissions paid to the securities firm, exchange fees, and—if you’re trading overseas stocks—currency exchange fees.

The fee structures for domestic stocks and overseas stocks are completely different. In Korea, it’s mainly brokerage fees and institutional fees. For overseas stocks, in addition to that, there are also currency exchange fees—and if you’re trading U.S. stocks, SEC fees are included as well. That’s why overseas stock fees are usually much higher.

I also looked at how fees differ by securities firm, and they varied a lot depending on the trading size and the platform. For example, Kiwoom Securities’ HeroMaker4 has domestic stock fees at around 0.015%, which is extremely cheap, while other firms are around 0.1% to 0.15%. For overseas stocks, fees are quite similar across firms, at roughly 0.25%.

Each securities firm also often runs fee-waiver events for new customers. Mirae Asset offers a 90-day waiver, and Shinhan Investment offers a 1-year waiver for U.S. stocks, and so on. If you make good use of these benefits, you can save a significant amount on your initial trading costs.

I calculated how much fees affect profits, and it honestly was pretty shocking. When you trade 10 times with 1,000,000 won, even a difference of just 0.1% versus 0.2% in fees can change your final profit by 20,000 to 30,000 won. The more frequent your trades are and the larger the amounts, the bigger that gap becomes.

If you’re someone who does small-amount day trading, you especially need to watch out for fixed fees. Some firms, like Samsung Securities, charge a fixed fee of 1,500 won for trades under 10,000,000 won. If you trade 100 times, the fixed fees alone add up to 150,000 won.

To reduce fees, here are a few tips. First, make sure you accurately understand each securities firm’s fee structure. It’s important to check in advance whether there are fixed fees and how fees change depending on the trade amount. Second, take advantage of events aimed at new or dormant customers. If you apply right before you start trading, you can get the maximum benefit.

Third, manage your trading frequency and size strategically. Trading a larger amount at once may be more fee-efficient than making multiple small trades. Fourth, when trading overseas stocks, carefully check the exchange rate and currency exchange fees. The exchange rates used by securities firms are often worse than those at banks.

Fifth, choosing a securities firm that matches your trading pattern is key. If you mainly do small-amount day trading, choose a firm with no fixed fees. If you mainly trade large amounts, choose one that applies lower fees by amount bracket.

In the end, the most important thing is to compare securities firm fees accurately and choose the one that fits your trading style. Fees are a hidden variable that can make a big difference to your investment performance.