EWY vs. COST
EWY (iShares MSCI South Korea ETF) is Asia Pacific Equities fund tracking the MSCI Korea Index, while COST (Costco Wholesale Corporation) is a stock. Over the past 10 years, EWY returned 16.84%/yr vs 22.27%/yr for COST. At a 0.32 correlation, their price movements are largely independent.
Performance
EWY vs. COST - Performance Comparison
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Returns By Period
In the year-to-date period, EWY achieves a 103.10% return, which is significantly higher than COST's 14.24% return. Over the past 10 years, EWY has underperformed COST with an annualized return of 16.84%, while COST has yielded a comparatively higher 22.27% annualized return.
EWY
- 1D
- -0.75%
- 1M
- 4.68%
- YTD
- 103.10%
- 6M
- 117.85%
- 1Y
- 198.25%
- 3Y*
- 46.46%
- 5Y*
- 18.80%
- 10Y*
- 16.84%
COST
- 1D
- 0.68%
- 1M
- -4.91%
- YTD
- 14.24%
- 6M
- 11.38%
- 1Y
- -1.48%
- 3Y*
- 25.12%
- 5Y*
- 22.12%
- 10Y*
- 22.27%
EWY vs. COST - Yearly Performance Comparison
| 2026 (YTD) | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | |
|---|---|---|---|---|---|---|---|---|---|---|
EWY iShares MSCI South Korea ETF | 103.10% | 95.33% | -20.48% | 19.05% | -26.59% | -7.58% | 39.43% | 7.97% | -20.37% | 44.97% |
COST Costco Wholesale Corporation | 14.24% | -5.39% | 39.62% | 49.00% | -19.05% | 51.82% | 32.67% | 45.70% | 10.60% | 22.37% |
Correlation
The correlation between EWY and COST is -0.10, meaning they tend to move in opposite directions. This is especially valuable for risk management - when one declines, the other has historically tended to hold steady or rise.
| Correlation | |
|---|---|
Correlation (1Y) Calculated over the trailing 1-year period | -0.10 |
Correlation (3Y) Calculated over the trailing 3-year period | 0.14 |
Correlation (5Y) Calculated over the trailing 5-year period | 0.22 |
Correlation (10Y) Calculated over the trailing 10-year period | 0.26 |
Correlation (All Time) Calculated using the full available price history since May 12, 2000 | 0.32 |
The correlation between EWY and COST shifts across timeframes, from -0.10 (1 year) to 0.32 (all time), reflecting how their relationship changes across market environments.
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Return for Risk
EWY vs. COST — Risk / Return Rank
EWY
COST
EWY vs. COST - Risk-Adjusted Trends Comparison
This table presents a comparison of risk-adjusted performance metrics for iShares MSCI South Korea ETF (EWY) and Costco Wholesale Corporation (COST). Risk-adjusted metrics are performance indicators that assess an investment's returns in relation to its risk, enabling a more accurate comparison of different investment options.
Values are calculated on a 1-year rolling basis and updated daily. Risk-adjusted metrics are more stable over longer periods — use the period switch above to explore them.
| EWY | COST | Difference | |
|---|---|---|---|
| Sharpe ratioReturn per unit of total volatility | +4.37 | ||
| Sortino ratioReturn per unit of downside risk | +4.06 | ||
| Omega ratioGain probability vs. loss probability | 1.59 | 1.00 | +0.59 |
| Calmar ratioReturn relative to maximum drawdown | 8.65 | -0.10 | +8.74 |
| Martin ratioReturn relative to average drawdown | 30.24 | -0.22 | +30.46 |
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Drawdowns
EWY vs. COST - Drawdown Comparison
The maximum EWY drawdown since its inception was -74.14%, which is greater than COST's maximum drawdown of -53.39%. Use the drawdown chart below to compare losses from any high point for EWY and COST.
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Drawdown Indicators
| EWY | COST | Difference | |
|---|---|---|---|
Max DrawdownLargest peak-to-trough decline | -74.14% | -53.39% | -20.75% |
Max Drawdown (1Y)Largest decline over 1 year | -23.08% | -15.14% | -7.94% |
Max Drawdown (3Y)Largest decline over 3 years | -27.36% | -20.74% | -6.62% |
Max Drawdown (5Y)Largest decline over 5 years | -48.55% | -31.40% | -17.15% |
Max Drawdown (10Y)Largest decline over 10 years | -49.73% | -31.40% | -18.33% |
Current DrawdownCurrent decline from peak | -8.88% | -10.23% | +1.35% |
Average DrawdownAverage peak-to-trough decline | -20.11% | -13.36% | -6.75% |
Ulcer IndexDepth and duration of drawdowns from previous peaks | 6.59% | 6.67% | -0.08% |
Volatility
EWY vs. COST - Volatility Comparison
iShares MSCI South Korea ETF (EWY) has a higher volatility of 25.64% compared to Costco Wholesale Corporation (COST) at 7.44%. This indicates that EWY's price experiences larger fluctuations and is considered to be riskier than COST based on this measure. The chart below showcases a comparison of their rolling one-month volatility.
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Volatility by Period
| EWY | COST | Difference | |
|---|---|---|---|
Volatility (1M)Calculated over the trailing 1-month period | 25.64% | 7.44% | +18.20% |
Volatility (6M)Calculated over the trailing 6-month period | 42.65% | 14.53% | +28.12% |
Volatility (1Y)Calculated over the trailing 1-year period | 46.51% | 18.80% | +27.71% |
Volatility (5Y)Calculated over the trailing 5-year period, annualized | 30.15% | 22.72% | +7.43% |
Volatility (10Y)Calculated over the trailing 10-year period, annualized | 28.06% | 21.95% | +6.11% |
Dividends
EWY vs. COST - Dividend Comparison
EWY's dividend yield for the trailing twelve months is around 1.03%, more than COST's 0.55% yield.
| Position | TTM | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
COST Costco Wholesale Corporation | 0.55% | 0.59% | 0.49% | 2.87% | 0.76% | 0.54% | 3.38% | 0.86% | 1.08% | 4.81% | 1.09% | 4.06% |
EWY iShares MSCI South Korea ETF | 1.03% | 2.10% | 2.55% | 2.52% | 1.23% | 2.16% | 0.73% | 2.10% | 1.34% | 2.90% | 1.21% | 2.42% |
Frequently Asked Questions
EWY and COST have a correlation of -0.10, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.
EWY has higher volatility (25.64%) compared to COST (7.44%). In terms of maximum drawdown, EWY dropped -74.14% vs COST's -53.39%.
EWY currently has the higher Sharpe Ratio (4.29 vs -0.08), meaning it's delivered slightly more return per unit of risk over the trailing 12 months. However, this ranking shifts over time - use the Risk/Return Score above for a more comprehensive view that combines Sharpe, Sortino, and other measures used by quantitative funds.
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