IWM vs. MDY

Last updated Jun 4, 2026

IWM (iShares Russell 2000 ETF) and MDY (SPDR S&P MidCap 400 ETF) are both exchange-traded funds - IWM is a Small Cap Blend Equities fund tracking the Russell 2000 Index, while MDY is a Small Cap Growth Equities fund tracking the S&P MidCap 400 Index. Both are passively managed. Over the past 10 years, IWM returned 10.93%/yr vs 11.04%/yr for MDY. Their correlation of 0.95 suggests significant overlap in exposure. IWM charges 0.19%/yr vs 0.23%/yr for MDY.

Performance

IWM vs. MDY - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in iShares Russell 2000 ETF (IWM) and SPDR S&P MidCap 400 ETF (MDY). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, IWM achieves a 17.07% return, which is significantly higher than MDY's 13.91% return. Both investments have delivered pretty close results over the past 10 years, with IWM having a 10.93% annualized return and MDY not far ahead at 11.04%.

IWM

• 1D: -1.37%
• 1M: 3.52%
• YTD: 17.07%
• 6M: 15.83%
• 1Y: 39.10%
• 3Y*: 17.88%
• 5Y*: 6.11%
• 10Y*: 10.93%

MDY

• 1D: -0.09%
• 1M: 3.81%
• YTD: 13.91%
• 6M: 14.15%
• 1Y: 25.00%
• 3Y*: 15.77%
• 5Y*: 7.92%
• 10Y*: 11.04%

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

IWM vs. MDY - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
IWM iShares Russell 2000 ETF	17.07%	12.66%	11.38%	16.83%	-20.48%	14.54%	20.03%	25.39%	-11.12%	14.58%
MDY SPDR S&P MidCap 400 ETF	13.91%	7.19%	13.64%	16.07%	-13.28%	24.53%	13.50%	25.78%	-11.29%	15.93%

Correlation

The correlation between IWM and MDY is 0.92, indicating a strong positive relationship between their price movements. Combining them offers limited diversification - they tend to fall together during downturns.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.92
Correlation (3Y) Calculated over the trailing 3-year period	0.94
Correlation (5Y) Calculated over the trailing 5-year period	0.95
Correlation (10Y) Calculated over the trailing 10-year period	0.95
Correlation (All Time) Calculated using the full available price history since May 30, 2000	0.95

The correlation between IWM and MDY has been stable across timeframes, ranging from 0.92 to 0.95 - a consistent structural relationship.

IWM vs. MDY - Sectors Allocation Comparison

Sectors	IWM	MDY
Technology	19.5%	15.4%
Industrials	17.1%	25.1%
Financial Services	15.8%	13.9%
Healthcare	15.8%	8.7%
Consumer Cyclical	7.8%	10.8%
Energy	6.0%	5.6%
Real Estate	5.7%	7.7%
Basic Materials	4.5%	4.8%
Utilities	3.0%	3.1%
Consumer Defensive	2.1%	3.8%
Communication Services	2.0%	1.0%

Return for Risk

IWM vs. MDY — Risk / Return Rank

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

IWM

IWM Risk / Return Rank: 62
IWM Sharpe Ratio Rank: 59
IWM Sortino Ratio Rank: 59
IWM Omega Ratio Rank: 53
IWM Calmar Ratio Rank: 70
IWM Martin Ratio Rank: 67

MDY

MDY Risk / Return Rank: 50
MDY Sharpe Ratio Rank: 46
MDY Sortino Ratio Rank: 46
MDY Omega Ratio Rank: 44
MDY Calmar Ratio Rank: 56
MDY Martin Ratio Rank: 58

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.

IWM vs. MDY - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for iShares Russell 2000 ETF (IWM) and SPDR S&P MidCap 400 ETF (MDY). 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.

	IWM	MDY	Difference
Sharpe ratio: Return per unit of total volatility	2.05	1.63	+0.43
Sortino ratio: Return per unit of downside risk	2.85	2.39	+0.47
Omega ratio: Gain probability vs. loss probability	1.34	1.29	+0.05
Calmar ratio: Return relative to maximum drawdown	3.56	2.85	+0.72
Martin ratio: Return relative to average drawdown	12.64	10.38	+2.27
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

IWM vs. MDY - Sharpe Ratio Comparison

The current IWM Sharpe Ratio is 2.05, which is comparable to the MDY Sharpe Ratio of 1.63. The chart below compares the historical Sharpe Ratios of IWM and MDY, 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

	IWM	MDY	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.05	1.63	+0.43
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.27	0.40	-0.13
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.48	0.52	-0.05
Sharpe Ratio (All Time) Calculated using the full available price history	0.37	0.53	-0.16

Drawdowns

IWM vs. MDY - Drawdown Comparison

The maximum IWM drawdown since its inception was -59.05%, which is greater than MDY's maximum drawdown of -55.33%. Use the drawdown chart below to compare losses from any high point for IWM and MDY.

Drawdown Indicators

	IWM	MDY	Difference
Max Drawdown Largest peak-to-trough decline	-59.05%	-55.33%	-3.72%
Max Drawdown (1Y) Largest decline over 1 year	-11.03%	-8.82%	-2.21%
Max Drawdown (3Y) Largest decline over 3 years	-27.50%	-24.03%	-3.47%
Max Drawdown (5Y) Largest decline over 5 years	-31.91%	-24.03%	-7.88%
Max Drawdown (10Y) Largest decline over 10 years	-41.13%	-42.22%	+1.09%
Current Drawdown Current decline from peak	-1.49%	-0.09%	-1.40%
Average Drawdown Average peak-to-trough decline	-10.77%	-7.03%	-3.74%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.10%	2.42%	+0.68%

Volatility

IWM vs. MDY - Volatility Comparison

iShares Russell 2000 ETF (IWM) has a higher volatility of 5.75% compared to SPDR S&P MidCap 400 ETF (MDY) at 4.33%. This indicates that IWM's price experiences larger fluctuations and is considered to be riskier than MDY based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	IWM	MDY	Difference
Volatility (1M) Calculated over the trailing 1-month period	5.75%	4.33%	+1.42%
Volatility (6M) Calculated over the trailing 6-month period	13.53%	11.28%	+2.25%
Volatility (1Y) Calculated over the trailing 1-year period	19.20%	15.48%	+3.72%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	22.52%	19.77%	+2.75%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	23.04%	21.19%	+1.85%

IWM vs. MDY - Expense Ratio Comparison

IWM has a 0.19% expense ratio, which is lower than MDY's 0.23% expense ratio. Despite the difference, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.

Dividends

IWM vs. MDY - Dividend Comparison

IWM's dividend yield for the trailing twelve months is around 0.88%, less than MDY's 1.04% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
IWM iShares Russell 2000 ETF	0.88%	1.04%	1.15%	1.35%	1.48%	0.94%	1.04%	1.26%	1.40%	1.26%	1.38%	1.54%
MDY SPDR S&P MidCap 400 ETF	1.04%	1.15%	1.18%	1.21%	1.37%	0.96%	1.12%	1.34%	1.39%	1.18%	1.31%	1.35%

Frequently Asked Questions

Can I hold both IWM and MDY in my portfolio?

With a correlation of 0.92, IWM and MDY move almost identically. Holding both adds very little diversification - you're essentially doubling your position in the same market segment. Choosing one is usually more capital-efficient.

Which is riskier, IWM or MDY?

IWM has higher volatility (5.75%) compared to MDY (4.33%). In terms of maximum drawdown, IWM dropped -59.05% vs MDY's -55.33%.

Which ETF is better, IWM or MDY?

On 10-year performance, MDY leads with 11.04% vs 10.93% for IWM. On fees, IWM is cheaper at 0.19% per year. On volatility, MDY has been the lower-risk option at 4.33%. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF has performed better, IWM or MDY?

Over the 10-year period, MDY has performed better with a 11.04% return vs 10.93%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

Which ETF is cheaper, IWM or MDY?

IWM is cheaper with a 0.19% expense ratio, compared with 0.23% for MDY.

Which ETF pays a higher dividend yield, IWM or MDY?

MDY has the higher dividend yield at 1.04%, compared with 0.88% for IWM.

What is the main difference between IWM and MDY?

IWM is categorized as Small Cap Blend Equities, while MDY is Small Cap Growth Equities. IWM tracks Russell 2000 Index, while MDY tracks S&P MidCap 400 Index. They also come from different issuers: iShares and State Street. Their fees differ too: 0.19% for IWM and 0.23% for MDY.

Which has better risk-adjusted returns?

IWM currently has the higher Sharpe Ratio (2.05 vs 1.63), 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.