US ETF Investment Guide for Korean Investors: From Brokerage Account Setup to Taxes

To buy US ETFs, Korean investors need an overseas stock trading account. Major Korean brokerages — Kiwoom, Mirae Asset, Samsung Securities, NH Investment, Korea Investment, and Toss Securities — all offer US stock trading and allow fully online account opening via mobile apps.

The key comparison points are trading commissions and FX spread. Trading fees range from 0.07% to 0.25% depending on the broker, and promotional zero-fee offers are common for new accounts. Currency exchange spreads also vary, so it is important to compare the total effective cost (trading fee + FX spread) across brokers.

Typical account opening steps:

- Install the brokerage app and complete non-face-to-face account opening (ID scan, identity verification)

- Agree to overseas stock trading terms (separate consent required)

- Confirm foreign currency securities account activation

- Deposit KRW, exchange to USD, and you are ready to buy

Buying US ETFs requires converting Korean won (KRW) to US dollars (USD). There are two main approaches.

Auto exchange is handled automatically by the brokerage at the time of purchase. It is convenient but often comes with a lower preferential exchange rate, resulting in higher effective FX costs.

Manual exchange means converting KRW to USD in advance through the brokerage or bank app. By taking advantage of FX discount promotions (up to 95% off the spread), you can significantly reduce exchange costs. Most brokerages allow you to hold a USD balance, so you can exchange when the rate is favorable and buy ETFs at your preferred timing.

Exchange timing tips:

- Split your exchanges over time when the KRW is strong to lower your average exchange cost.

- Set exchange rate alerts and convert when your target rate is reached.

- Consider dollar-cost-averaging your FX conversions to mitigate currency fluctuation risk.

Once you have USD in your account, you can buy US ETFs. US market trading hours are 11:30 PM to 6:00 AM KST (10:30 PM to 5:00 AM during daylight saving time). Most Korean brokerages also support pre-market and after-hours trading.

There are three main order types:

Market Order: Executes immediately at the current market price. Use it when you need a quick fill, but be aware that low-liquidity ETFs may fill at a higher price than expected.

Limit Order: You set a specific price, and the order only fills at that price or better. This gives you price control but may not execute if the price is never reached. This is the most recommended order type for beginners.

Pre-set Order (Extended Hours): Place your order before the market opens. This is useful for working professionals who cannot stay up during US market hours (late night in Korea).

Buying tips:

- Large ETFs like VOO, QQQ, and VTI have deep liquidity, making market orders relatively safe.

- Some brokerages support fractional shares, allowing small investments even in high-priced ETFs.

- For your first trade, place a small test order to get familiar with the execution process.

Korean investors in US ETFs need to understand two main taxes: capital gains tax and dividend withholding tax.

Capital Gains Tax:

Profits from selling overseas stocks are taxed at 22% (20% income tax + 2% local tax) on annual net gains exceeding KRW 2.5 million (approximately USD 1,800). Net gains are calculated by offsetting losses against gains from January 1 to December 31. If your net profit exceeds the threshold, you must file and pay by the following May.

Tax-saving strategies:

- Use tax-loss harvesting — sell losing positions near year-end to offset gains.

- Spread your selling across years to stay under the KRW 2.5 million tax-free threshold.

Dividend Withholding Tax:

Dividends from US ETFs are subject to 15% withholding at source under the Korea-US tax treaty. Since the Korean domestic dividend tax rate (15.4%) is nearly the same, no additional tax is generally owed. However, if your total financial income (interest + dividends) exceeds KRW 20 million per year, you become subject to comprehensive financial income taxation.

Filing:

- Capital gains: Many Korean brokerages offer a tax filing assistance service. You can also file directly through the National Tax Service (Hometax) website.

- Dividends: Since tax is withheld at source in the US, no separate filing is required (unless subject to comprehensive taxation).