If you had bought Samsung Electronics every month for the past 10 years

For Samsung Electronics, 2016 was a year of opportunity. The stock started around KRW 1.2 million (converted to today's share-price basis) and, riding the semiconductor super-cycle, rose sharply to a peak of KRW 96,800 by the end of 2021.

But from 2022, the stock plunged amid a deteriorating semiconductor cycle and the shock of global tightening. By the end of 2022, it had fallen to the KRW 48,000 range, about -50% from the peak. If you had kept up recurring investing even in this period, you would have gained a chance to buy heavily at the lows.

As of 2026, the estimated value is about $23k (pre-tax) — roughly a 29% gain over the total principal of about $18k. In XIRR terms, that is about 2.6%. This is a very weak result compared with the S&P 500 over the same period.

Over the same period (2016–2026), investing in the S&P 500 under the same conditions would have produced a very different estimated result. This case illustrates the difference between diversification (index investing) and single-stock investing.

Samsung Electronics is Korea's largest company and a global semiconductor firm. Even so, its 10-year performance was lower than the index. Individual companies carry company-specific risks that an index does not (industry cycles, management risk, and so on).

What matters is that over these 10 years, you experienced a halving (-50%) from the peak. Someone who bought at the late-2021 peak may still be at a loss through 2026.