What the Investment Simulator calculates

It answers the question “what if I had bought that stock back then?” using real historical data. Prices are dividend-adjusted closes (dividends assumed reinvested), and the KRW/USD exchange rate at both the start and the end of the period is applied, so the result is a won-denominated value as of today. For comparison, the same amount invested in SPY (an S&P 500 ETF) over the identical period is shown alongside.

Data covers the supported universe (100 ETFs and large caps) and is refreshed from closing prices each trading day. Taxes and trading commissions are not included — this is a plain price-and-exchange-rate calculation. Actual results would differ because of taxes, fees and execution timing, and past performance does not guarantee future returns. This tool is not investment advice.

Worked example — following the numbers

The formula is final value = investment × price ratio × FX ratio (price ratio = end-date close ÷ start-date close, FX ratio = end-date KRW/USD rate ÷ start-date KRW/USD rate). Example (hypothetical numbers — not an actual stock's actual return): if a stock closed at $100 three years ago and $150 today, the price ratio is 1.5. If the exchange rate was 1,300 KRW/USD three years ago and 1,380 KRW/USD today, the FX ratio is 1,380 ÷ 1,300 ≈ 1.0615. Investing 10,000,000 KRW would give a final value of 10,000,000 × 1.5 × 1.0615 ≈ 15,920,000 KRW (total return +59.2%). The won-denominated return is the product of "how much the stock rose in dollars" and "how much the dollar rose against the won" — so the same stock can produce a different result purely from currency moves.

What's included, what isn't

Included: dividend-adjusted closing prices (dividends assumed reinvested), the KRW/USD exchange rate at the start and end dates. Not included: trading commissions, FX conversion spreads, capital gains/dividend taxes, buying or selling in installments, and any exchange-rate movement between the start and end dates (only those two points are used). If you actually bought and sold in tranches during that period, your real result would differ from this calculation.

How to read the result

Maximum Drawdown (MDD) is the largest peak-to-trough decline the stock experienced after your start date — even a positive final return can hide a stretch where you would have needed to tolerate a large paper loss. A lower result than the SPY comparison does not mean the stock was a bad choice — this is the outcome for one specific start date, and shifting the start date by even a single day can change the return significantly (especially for leveraged ETFs like TQQQ or SOXL, which are more sensitive to the exact start date because of their volatility). This tool uses actual past prices; to compare after-tax outcomes from price, dividend and FX assumptions you set yourself, use the asset comparison calculator (assumption-based, not historical data).

When your input is out of range

A ticker outside the supported list (100 ETFs and large caps) returns an "unsupported ticker" error. The period must be one of 1, 3, 5, or 10 years. The investment amount must be between 10,000 and 10,000,000,000 KRW. For a recently listed stock that doesn't yet have enough history for the period you chose (if the actual data start date is more than 45 days later than the requested start date), the tool shows "data is not yet available" instead of calculating — it does not force an inaccurate number.

Assumptions and limits

Both price and FX are closing-price based (not intraday execution prices). Only the start and end closing FX rates are used, so any swings in between don't show up in this calculation. Taxes (capital gains, etc.), trading commissions, and FX conversion fees are entirely excluded — this is a pre-tax, pre-fee calculation, and past performance does not guarantee future returns. This tool is a reference for the "what if I had bought back then" question using historical data — it does not recommend any specific stock or timing.