MDY vs. IWM

Last updated Jun 3, 2026

MDY (SPDR S&P MidCap 400 ETF) and IWM (iShares Russell 2000 ETF) are both exchange-traded funds - MDY is a Small Cap Growth Equities fund tracking the S&P MidCap 400 Index, while IWM is a Small Cap Blend Equities fund tracking the Russell 2000 Index. Both are passively managed. Over the past 10 years, MDY returned 11.05%/yr vs 11.08%/yr for IWM. Their correlation of 0.95 suggests significant overlap in exposure. MDY charges 0.23%/yr vs 0.19%/yr for IWM.

Performance

MDY vs. IWM - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in SPDR S&P MidCap 400 ETF (MDY) 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, MDY achieves a 14.02% return, which is significantly lower than IWM's 18.69% return. Both investments have delivered pretty close results over the past 10 years, with MDY having a 11.05% annualized return and IWM not far ahead at 11.08%.

MDY

• 1D: 0.90%
• 1M: 3.28%
• YTD: 14.02%
• 6M: 15.05%
• 1Y: 26.67%
• 3Y*: 15.81%
• 5Y*: 8.07%
• 10Y*: 11.05%

IWM

• 1D: 0.93%
• 1M: 4.43%
• YTD: 18.69%
• 6M: 19.57%
• 1Y: 43.31%
• 3Y*: 18.42%
• 5Y*: 6.49%
• 10Y*: 11.08%

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

MDY vs. IWM - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
MDY SPDR S&P MidCap 400 ETF	14.02%	7.19%	13.64%	16.07%	-13.28%	24.53%	13.50%	25.78%	-11.29%	15.93%
IWM iShares Russell 2000 ETF	18.69%	12.66%	11.38%	16.83%	-20.48%	14.54%	20.03%	25.39%	-11.12%	14.58%

Correlation

The correlation between MDY and IWM 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	0.96
Correlation (All Time) Calculated using the full available price history since May 30, 2000	0.95

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

MDY vs. IWM - Sectors Allocation Comparison

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

Return for Risk

MDY vs. IWM — Risk / Return Rank

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

MDY

MDY Risk / Return Rank: 54
MDY Sharpe Ratio Rank: 49
MDY Sortino Ratio Rank: 51
MDY Omega Ratio Rank: 48
MDY Calmar Ratio Rank: 60
MDY Martin Ratio Rank: 61

IWM

IWM Risk / Return Rank: 69
IWM Sharpe Ratio Rank: 68
IWM Sortino Ratio Rank: 67
IWM Omega Ratio Rank: 60
IWM Calmar Ratio Rank: 77
IWM Martin Ratio Rank: 73

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.

MDY vs. IWM - Risk-Adjusted Trends Comparison

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

	MDY	IWM	Difference
Sharpe ratio Return per unit of total volatility	1.73	2.27	-0.54
Sortino ratio Return per unit of downside risk	2.52	3.12	-0.60
Omega ratio Gain probability vs. loss probability	1.31	1.37	-0.07
Calmar ratio Return relative to maximum drawdown	3.01	3.97	-0.96
Martin ratio Return relative to average drawdown	10.99	14.12	-3.12
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

MDY vs. IWM - Sharpe Ratio Comparison

The current MDY Sharpe Ratio is 1.73, which is comparable to the IWM Sharpe Ratio of 2.27. The chart below compares the historical Sharpe Ratios of MDY 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

	MDY	IWM	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.73	2.27	-0.54
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.41	0.29	+0.12
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.52	0.48	+0.04
Sharpe Ratio (All Time) Calculated using the full available price history	0.53	0.37	+0.16

Drawdowns

MDY vs. IWM - Drawdown Comparison

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

Drawdown Indicators

	MDY	IWM	Difference
Max Drawdown Largest peak-to-trough decline	-55.33%	-59.05%	+3.72%
Max Drawdown (1Y) Largest decline over 1 year	-8.82%	-11.03%	+2.21%
Max Drawdown (3Y) Largest decline over 3 years	-24.03%	-27.50%	+3.47%
Max Drawdown (5Y) Largest decline over 5 years	-24.03%	-31.91%	+7.88%
Max Drawdown (10Y) Largest decline over 10 years	-42.22%	-41.13%	-1.09%
Current Drawdown Current decline from peak	0.00%	-0.13%	+0.13%
Average Drawdown Average peak-to-trough decline	-7.03%	-10.77%	+3.74%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.42%	3.10%	-0.68%

Volatility

MDY vs. IWM - Volatility Comparison

The current volatility for SPDR S&P MidCap 400 ETF (MDY) is 4.40%, while iShares Russell 2000 ETF (IWM) has a volatility of 5.56%. This indicates that MDY experiences smaller price fluctuations and is considered to be less risky than IWM based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	MDY	IWM	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.40%	5.56%	-1.16%
Volatility (6M) Calculated over the trailing 6-month period	11.30%	13.52%	-2.22%
Volatility (1Y) Calculated over the trailing 1-year period	15.48%	19.14%	-3.66%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	19.77%	22.52%	-2.75%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	21.19%	23.04%	-1.85%

MDY vs. IWM - Expense Ratio Comparison

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

Dividends

MDY vs. IWM - Dividend Comparison

MDY's dividend yield for the trailing twelve months is around 1.04%, more than IWM's 0.87% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
IWM iShares Russell 2000 ETF	0.87%	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 MDY and IWM in my portfolio?

With a correlation of 0.92, MDY and IWM 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, MDY or IWM?

IWM has higher volatility (5.56%) compared to MDY (4.40%). In terms of maximum drawdown, MDY dropped -55.33% vs IWM's -59.05%.

Which ETF is better, MDY or IWM?

On 10-year performance, IWM leads with 11.08% vs 11.05% for MDY. On fees, IWM is cheaper at 0.19% per year. On volatility, MDY has been the lower-risk option at 4.40%. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF has performed better, MDY or IWM?

Over the 10-year period, IWM has performed better with a 11.08% return vs 11.05%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

Which ETF is cheaper, MDY or IWM?

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

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

MDY has the higher dividend yield at 1.04%, compared with 0.87% for IWM.

What is the main difference between MDY and IWM?

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

Which has better risk-adjusted returns?

IWM currently has the higher Sharpe Ratio (2.27 vs 1.73), 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.