Stock prices and the KRW price of the dollar move together.

Even if the dollar price of a stock remains the same after purchase, an increase in the KRW/USD exchange rate can increase the asset's value in KRW. Conversely, if the exchange rate falls, the value may decrease. Gains from exchange rate fluctuations are called exchange gains, and losses are called exchange losses.

If the dollar weakens while stock prices rise, your profit converted to KRW may decrease. Sometimes, a stronger dollar can partially offset a decline in stock prices. The two prices do not always move in opposite directions, nor do they always hedge against each other's losses.

Simply adding the two rates of return is not accurate.

For a single investment without changes in quantity, dividends, additional deposits/withdrawals, fees, or taxes, the KRW return can be calculated as: (Selling dollar price ÷ Buying dollar price) × (Final exchange rate ÷ Initial exchange rate) − 1. The exchange rate uses the KRW amount per 1 USD based on the same standard.

The same formula can be written as (1 + dollar stock return rate) × (1 + exchange rate change rate) − 1. When comparing up to the actual currency exchange, you must use the applied exchange rate from when you first bought the dollars and the applied exchange rate from when you finally sold them. Deducting costs already included in those exchange rates would result in double counting.

+10% in dollars, approximately +1.54% in KRW.

Let's compare by assuming you bought one share of stock worth 100 USD at 1 USD per 1,300 KRW. The starting amount is 130,000 KRW. The example below is for calculation principles and excludes dividends, fees, and taxes.

Selling stocks and converting dollars are separate steps.

If you have secured 110 USD by selling the stock, you are no longer subject to changes in the stock price, but the value evaluated in KRW will continue to fluctuate based on the exchange rate as long as you hold the dollars. It is easier to understand if you record the time you finished trading the stock in dollars and the time you converted to KRW separately.

The KRW valuation profit and loss in the app may vary depending on the exchange rate used for valuation and the reference point in time. The valuation amount that has not yet been exchanged may differ from the actual KRW received upon currency exchange. This explanation distinguishes between economic profit and loss and is not a standard for determining the timing of tax liabilities or reported amounts.

If you have bought and sold multiple times, you need records for each transaction.

If there are additional purchases, partial sales, dividends, commissions, or multiple currency exchanges, it is difficult to calculate the total account return using only the single investment formula above. You must organize dollar transaction history, KRW deposits/withdrawals, and the actual applied exchange rates in chronological order.

If you already held dollars, the comparison question changes depending on whether you look from the time you started holding dollars or from the day you bought the stocks. Set a starting point first and compare using the same criteria. For dividends, check the payment currency and actual amount received; for taxes, check the separate applicable standards.

The exchange rate is also not a number that can be predicted with certainty.

The fact that the dollar has risen or fallen significantly does not determine its next direction. In addition to stock risk, consider the timing of your KRW funding needs, exchange costs, and the scale of your dollar holdings. This is not a guide suggesting specific exchange rates for buying or selling.

When recording stock trading results, placing dollar-based and KRW-based figures side-by-side makes it easier to see what influenced performance. The dollar-based simulated return on WAPE does not guarantee the actual KRW profit, which reflects the brokerage's actual currency exchange, costs, and taxes.

Check what you have read.

• Have you set the start and end points for the stock price and exchange rate?
• Have you separated your KRW and dollar gains and losses?
• Have you distinguished between the actual applied exchange rate and the valuation exchange rate?
• Did you miss any costs or deduct them twice?

Apply what you read to the actual screen

Try it on WAPE

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