Rate of Return
Overview
Rate of return (收益率, rate of return) is a metric that expresses, as a ratio, the profit or loss earned over a certain period relative to the invested capital (principal). It is a key measure that allows performance to be compared regardless of investment size, and it is used in almost all economic activities, from stocks, bonds, real estate, and deposits to corporate finance and policy evaluation. In that it asks not 'how much did you earn?' but 'how much did you earn relative to the capital invested?', the rate of return can be called the language of finance itself.
Main Content
Definition and Basic Calculation
The most basic simple rate of return is calculated as follows.
> Simple rate of return (%) = (final value − initial investment + interim cash flows) ÷ initial investment × 100
For example, if 10 million won was invested and one year later the valuation became 11 million won, the rate of return is 10%. If there were dividends or interest, these are added as interim cash flows to become the 'total return.' Conversely, after deducting fees, taxes, and management fees, it becomes the after-tax rate of return that the investor actually receives.
Simple Return and Annualized Return (CAGR)
For investments spanning multiple years, cumulative return and average annual return must be distinguished. The annualized return, namely the compound annual growth rate (CAGR), is calculated as (final value ÷ initial value)^(1/n) − 1. If a cumulative return of 100% was achieved over 10 years, the annualized figure is only about 7.2%. Also, for highly volatile assets, the arithmetic average return tends to overestimate the actually realized return, so it is more accurate to view it using the geometric mean (compound basis).
Nominal Return and Real Return
Nominal return is a figure that does not reflect inflation, while real return is the return on a purchasing-power basis and is obtained as (1 + nominal)/(1 + inflation) − 1. If the nominal return is 5% and inflation is 3%, the real return is about 1.94%. In periods of severe inflation, even if the nominal return appears high, it may be a loss on a real basis.
Expected Return, Risk, and Risk-Adjusted Return
Expected return is the probability-weighted average of the returns of each scenario. In general, the greater the risk, the higher the return investors require, and this is called the risk premium added on top of the risk-free rate. Representative risk-adjusted return metrics include the Sharpe ratio, information ratio, and Treynor ratio, which use volatility (standard deviation) as a proxy for risk and divide excess return by volatility.
Various Return Metrics
- ROI (Return on Investment): The ratio of net profit to the principal invested.
- ROE / ROA: Return on equity and return on assets, which measure a company's efficiency in utilizing capital.
- IRR (Internal Rate of Return): The discount rate that makes the net present value of cash flows zero, used to evaluate long-term projects.
- YTM (Yield to Maturity): The annualized return when a bond is held to maturity.
- Dividend Yield: The ratio of annual dividends to the stock price.
- Capital Gains Yield: The return calculated solely from gains arising from price increases.
Compounding and the Rule of 72
When returns are reinvested, a compounding effect occurs. The time required for the principal to double can be approximated by '72 ÷ annual return' (the Rule of 72). At 6% per year, it takes about 12 years; at 12% per year, about 6 years. This shows that the rate of return is a decisive variable in long-term performance.
Latest Trends
In the financial markets of 2024–2025, the rate of return again became a major topic. As major central banks maintained high interest rates and then shifted to cuts, the yields on deposits, MMFs, and short-term bonds fluctuated significantly, and cash-like assets that had been called 'non-interest-bearing assets' re-emerged as attractive yield assets. At the same time, the 10-year U.S. Treasury yield has fluctuated sensitively according to inflation indicators and employment data, serving as a benchmark for asset prices worldwide.
Investor behavior has also changed. The long-term annualized returns of TDFs, ETFs, and personal pensions, which spread during the ultra-low interest rate period, began to be actually verified, and concepts such as the 'yield curve' and 'after-tax return' became everyday terms even for individual investors. While AI-related stocks and the semiconductor sector recorded high capital gains yields in a short period, real estate has continued a phase in which rental yields and capital gains yields diverge due to sluggish transactions and interest rate burdens. In addition, amid aging populations and pension reform discussions, how to set a 'target return' and manage risk has emerged as a policy task, and voices demanding disclosure of real, after-fee-and-tax returns are growing louder. The weak won and the expansion of overseas investment are also highlighting the importance of 'currency-converted returns' that reflect exchange rate fluctuations.
Related Topics
- [[Investment]]
- [[Stocks]]
- [[Interest Rates]]
- [[Compound Interest]]
- [[Risk Management]]