Average cost when you buy more than once
If you buy the same stock at different prices — averaging down after a fall, or adding on the way up — your average cost is the total amount paid divided by the number of shares. It is not the simple average of the prices, because each purchase is weighted by how many shares you bought. The calculator adds up each line, including fees if you enter them, and shows the break-even price: the share price at which selling everything returns exactly what you paid.
Return in two currencies
When you buy a Korean stock with US dollars (or any other currency), your result depends on two things: the change in the share price in Korean won, and the change in the won exchange rate between buying and selling. A stock can rise 10% in won while the won weakens 8% against the dollar, leaving you with a small gain in dollars — or the reverse. The calculator converts each purchase at the exchange rate you enter for that day and converts the current value at today's rate, so you see both returns side by side.
Separating the currency effect
The difference between your home-currency return and your local-currency return is the currency effect. The calculator reports it in money and in percentage points, so you can tell whether a gain came from the company or from the exchange rate. This matters for decisions: a currency gain can disappear when the rate moves back, while a change in the share price reflects the business and the market's view of it.
How to enter exchange rates
Enter the rate as "won per one unit of your currency" — for example 1,380 won per dollar. Use the rate your broker actually applied, which includes its currency spread; the rate in the news is usually a mid-market rate and slightly better than what investors get. Fees and taxes on sale are not included unless you add them to the cost.
Information only — not investment advice. Headlines and filing titles are machine-translated from Korean; each links to the original Korean source. Updated: