When exchanging dollars, does a higher exchange rate preference mean there are no costs?
The base exchange rate on the screen may differ from the rate applied to you. Read the exchange spread, preferential rate, and automatic exchange conditions separately.
Table of contents
Remember this first
First, 3 things to remember
- 1The base exchange rate may differ from the actual exchange rate applied when buying or selling dollars.
- 2Exchange rate preferential treatment is usually a discount on the currency exchange cost, not a discount on the dollar principal.
- 3Check the trading fees, currency exchange costs, and conditions by time of day individually.
First, read how many KRW 1 dollar is worth.
The dollar price of a US-listed stock and the KRW expenditure of a Korean investor are different figures. If the KRW/USD exchange rate is 1 KRW per 1,300 dollar, then excluding costs, 100 dollars requires 130,000 KRW. If it becomes 1,400 KRW, the same 100 dollars requires 140,000 KRW.
All exchange rates in this article are based on "KRW per 1 USD." If the number rises, more KRW is required to purchase dollars. If your app displays the exchange rate in a different direction, you should not interpret it in the same way.
Fees may be included in the exchange rate.
Brokerage firms may offer different applicable exchange rates when buying and selling foreign currency. The difference added to or subtracted from the base exchange rate is called the spread, and currency exchange costs may be reflected within this. Just because there is no separate withdrawal record for a "currency exchange fee" does not mean there are no costs.
Base exchange rates, buy/sell conditions, and account benefits vary by brokerage firm. Rather than just comparing the preference rate numbers, you should compare the final KRW to be paid and the dollars to be received at the same time and for the same amount. The current benefits of a specific brokerage firm cannot be applied to other firms or all accounts.
What is 90% preferential rate a 90% of?
Let's assume the base exchange rate is 1,300 KRW and the one-way currency exchange cost is 10 KRW per dollar. If you discount that cost by 90%, the remaining cost is 1 KRW. It does not mean the dollar price itself is discounted by 90%.
| Condition | Virtual applicable exchange rate |
|---|---|
| Dollar purchase · No preference | 1,310 KRW = 1,300 KRW + 10 KRW |
| Dollar purchase · 90% cost discount | 1,301 KRW = 1,300 KRW + 1 KRW |
| Dollar sell · 90% cost preference | 1,299 KRW = 1,300 KRW − 1 KRW |
If you buy and then sell, consider the costs on both sides.
In the previous scenario, you need 1,301,000 KRW to buy 1,000 dollars. If you convert it all back to KRW while the base exchange rate remains the same, you receive 1,299,000 KRW. The difference of 2,000 KRW is the total exchange cost.
You must also check what costs are being discounted and based on what criteria for "100% exchange rate preference." There may be cases where the base exchange rates for buying and selling are different, or there may be times and currencies excluded from the preference. Currency exchange benefits do not mean that stock trading commissions or other product costs are free.
KRW-denominated orders are also affected by the exchange rate.
Even if you enter the order amount in KRW, the brokerage's currency exchange or KRW order service may be triggered during the purchase and settlement process for dollar-denominated products. You must check the service details to see if the applied exchange rate, preference, and settlement timing are the same for direct exchange and automatic exchange.
For after-hours currency exchange, there may be methods such as using a temporary exchange rate and then settling at the exchange rate at a set time. Samsung Securities also provides services where after-hours requests are actually processed at the exchange rate of the following business day. Not all brokerage firms process this at the same time or in the same way. Distinguish between the initially displayed amount and the final currency exchange details.
Write down the costs separately before trading.
You must read the event end date, whether you are a new customer, whether an application is required, and the preferential currency to know if it actually applies to your account. The final conditions displayed in your account are more important than the promotional title.
- 1
Check the applicable exchange rates and final amounts for both KRW to USD and USD to KRW.
- 2
Check the application conditions and settlement times for direct exchange, automatic exchange, and after-hours exchange.
- 3
Record stock buy/sell commissions and exchange costs as separate items.
- 4
After the currency exchange is finished, keep the actual records and calculate the results based on KRW.
You should not make such assumptions
“If there is a 95% exchange rate preference, is the dollar price discounted by 95%?”
It usually means a discount on the portion of the exchange cost eligible for the preference. You must check the brokerage's terms for the discount criteria and the final applied exchange rate.
Check what you have read.
- Have you distinguished between the base exchange rate and the actual applicable exchange rate?
- Have you calculated the currency exchange costs for both sides?
- Have you checked the benefit period and whether automatic exchange applies?
- Have you checked the stock trading commission separately?
Apply what you read to the actual screen
Try it on WAPE
Source and scope of verification
Reviewed · Version 1
- Overseas stock trading guide · Currency exchangeNew window
Samsung Securities · Verify 2026-10-20
Brokerage firm examples of currency exchange hours, after-hours exchange, and subsequent application of actual exchange rates - Examples of conditions for overseas stock commissions and exchange rate preferential eventsNew window
Samsung Securities · Verify 2026-10-20
Relationship between exchange rate preferential rates and currency exchange spreads · Examples of currency, target, and duration conditions for past events; not a recommendation for currently applicable benefits - Important notes on direct account currency exchangeNew window
Mirae Asset Securities · Verify 2026-10-20
Difference between buy/sell base exchange rates and currency exchange costs · Check preferential conditions by account and period - Foreign Currency Exchange · Quotes, Pricing and CostsNew window
SEC Investor.gov · Verify 2026-10-20
Meaning of exchange rates, currency notation, and bid-ask spreads · Refer only to pricing principles in FX margin product guides; general dollar exchange and FX margin are different transactions
This is educational material for observation and information comprehension. Hypothetical examples do not represent actual stocks or performance and do not provide buy or sell recommendations.