COST vs. IWM

Last updated Jun 9, 2026

COST (Costco Wholesale Corporation) is a stock, while IWM (iShares Russell 2000 ETF) is Small Cap Blend Equities fund tracking the Russell 2000 Index. Over the past 10 years, COST returned 22.25%/yr vs 10.78%/yr for IWM. At a 0.45 correlation, their price movements are largely independent.

Performance

COST vs. IWM - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Costco Wholesale Corporation (COST) and iShares Russell 2000 ETF (IWM). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, COST achieves a 13.35% return, which is significantly lower than IWM's 15.62% return. Over the past 10 years, COST has outperformed IWM with an annualized return of 22.25%, while IWM has yielded a comparatively lower 10.78% annualized return.

COST

• 1D: 0.30%
• 1M: -3.37%
• YTD: 13.35%
• 6M: 10.14%
• 1Y: -3.42%
• 3Y*: 25.18%
• 5Y*: 22.05%
• 10Y*: 22.25%

IWM

• 1D: 0.87%
• 1M: -0.02%
• YTD: 15.62%
• 6M: 13.83%
• 1Y: 35.52%
• 3Y*: 16.64%
• 5Y*: 5.48%
• 10Y*: 10.78%

*Multi-year figures are annualized to reflect compound growth (CAGR)

COST vs. IWM - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
COST Costco Wholesale Corporation	13.35%	-5.39%	39.62%	49.00%	-19.05%	51.82%	32.67%	45.70%	10.60%	22.37%
IWM iShares Russell 2000 ETF	15.62%	12.66%	11.38%	16.83%	-20.48%	14.54%	20.03%	25.39%	-11.12%	14.58%

Correlation

The correlation between COST and IWM is -0.03, meaning there is essentially no relationship between their price movements. Each responds to its own set of market drivers, making them strong candidates for combining in a diversified portfolio.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	-0.03
Correlation (3Y) Calculated over the trailing 3-year period	0.22
Correlation (5Y) Calculated over the trailing 5-year period	0.35
Correlation (10Y) Calculated over the trailing 10-year period	0.36
Correlation (All Time) Calculated using the full available price history since May 30, 2000	0.45

The correlation between COST and IWM shifts across timeframes, from -0.03 (1 year) to 0.45 (all time), reflecting how their relationship changes across market environments.

Return for Risk

COST vs. IWM — Risk / Return Rank

Compare risk-adjusted metric ranks to identify better-performing investments over the past 12 months.

COST

COST Risk / Return Rank: 32
COST Sharpe Ratio Rank: 34
COST Sortino Ratio Rank: 28
COST Omega Ratio Rank: 28
COST Calmar Ratio Rank: 35
COST Martin Ratio Rank: 33

IWM

IWM Risk / Return Rank: 63
IWM Sharpe Ratio Rank: 61
IWM Sortino Ratio Rank: 60
IWM Omega Ratio Rank: 54
IWM Calmar Ratio Rank: 71
IWM Martin Ratio Rank: 68

The rank (0–100) shows how this investment's returns compare to the risk taken. Higher = better. Based on the past 12 months of data, combining Sharpe, Sortino, and other metrics used by quantitative funds and institutional investors.

COST vs. IWM - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Costco Wholesale Corporation (COST) and iShares Russell 2000 ETF (IWM). 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.

	COST	IWM	Difference
Sharpe ratio: Return per unit of total volatility	-0.18	1.83	-2.01
Sortino ratio: Return per unit of downside risk	-0.13	2.54	-2.67
Omega ratio: Gain probability vs. loss probability	0.98	1.30	-0.32
Calmar ratio: Return relative to maximum drawdown	-0.22	3.24	-3.46
Martin ratio: Return relative to average drawdown	-0.51	11.44	-11.95
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

COST vs. IWM - Sharpe Ratio Comparison

The current COST Sharpe Ratio is -0.18, which is lower than the IWM Sharpe Ratio of 1.83. The chart below compares the historical Sharpe Ratios of COST and IWM, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Sharpe Ratios by Period

	COST	IWM	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	-0.18	1.83	-2.01
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.98	0.24	+0.73
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	1.02	0.47	+0.55
Sharpe Ratio (All Time) Calculated using the full available price history	0.59	0.36	+0.22

Drawdowns

COST vs. IWM - Drawdown Comparison

The maximum COST drawdown since its inception was -53.39%, smaller than the maximum IWM drawdown of -59.05%. Use the drawdown chart below to compare losses from any high point for COST and IWM.

Drawdown Indicators

	COST	IWM	Difference
Max Drawdown Largest peak-to-trough decline	-53.39%	-59.05%	+5.66%
Max Drawdown (1Y) Largest decline over 1 year	-15.38%	-11.03%	-4.35%
Max Drawdown (3Y) Largest decline over 3 years	-20.74%	-27.50%	+6.76%
Max Drawdown (5Y) Largest decline over 5 years	-31.40%	-31.91%	+0.51%
Max Drawdown (10Y) Largest decline over 10 years	-31.40%	-41.13%	+9.73%
Current Drawdown Current decline from peak	-10.93%	-2.71%	-8.22%
Average Drawdown Average peak-to-trough decline	-13.36%	-10.76%	-2.60%
Ulcer Index Depth and duration of drawdowns from previous peaks	7.15%	3.11%	+4.04%

Volatility

COST vs. IWM - Volatility Comparison

Costco Wholesale Corporation (COST) has a higher volatility of 7.71% compared to iShares Russell 2000 ETF (IWM) at 6.52%. This indicates that COST's price experiences larger fluctuations and is considered to be riskier than IWM based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	COST	IWM	Difference
Volatility (1M) Calculated over the trailing 1-month period	7.71%	6.52%	+1.19%
Volatility (6M) Calculated over the trailing 6-month period	14.53%	14.00%	+0.53%
Volatility (1Y) Calculated over the trailing 1-year period	18.79%	19.53%	-0.74%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	22.71%	22.58%	+0.13%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	21.95%	23.07%	-1.12%

Dividends

COST vs. IWM - Dividend Comparison

COST's dividend yield for the trailing twelve months is around 0.55%, less than IWM's 0.89% 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%
IWM iShares Russell 2000 ETF	0.89%	1.04%	1.15%	1.35%	1.48%	0.94%	1.04%	1.26%	1.40%	1.26%	1.38%	1.54%

Frequently Asked Questions

Can I hold both COST and IWM in my portfolio?

COST and IWM have a correlation of -0.03, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, COST or IWM?

COST has higher volatility (7.71%) compared to IWM (6.52%). In terms of maximum drawdown, COST dropped -53.39% vs IWM's -59.05%.

Which has better risk-adjusted returns?

IWM currently has the higher Sharpe Ratio (1.83 vs -0.18), 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.