MID vs. IWM
MID (American Century Mid Cap Growth Impact ETF) and IWM (iShares Russell 2000 ETF) are both exchange-traded funds - MID is a Mid Cap Growth Equities fund actively managed by American Century, while IWM is a Small Cap Blend Equities fund tracking the Russell 2000 Index. MID is actively managed, while IWM is passively managed. Over the past 5 years, MID returned 2.57%/yr vs 6.99%/yr for IWM. Their 0.79 correlation means they have sometimes moved together and sometimes differently. MID charges 0.45%/yr vs 0.19%/yr for IWM.
Performance
MID vs. IWM - Performance Comparison
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Returns By Period
In the year-to-date period, MID achieves a 2.51% return, which is significantly lower than IWM's 18.79% return.
MID
- 1D
- 0.19%
- 1M
- -2.00%
- 6M
- 1.56%
- YTD
- 2.51%
- 1Y
- 1.83%
- 3Y*
- 11.74%
- 5Y*
- 2.57%
- 10Y*
- —
- ALL TIME*
- 9.07%
IWM
- 1D
- -0.48%
- 1M
- -2.14%
- 6M
- 12.62%
- YTD
- 18.79%
- 1Y
- 36.90%
- 3Y*
- 15.11%
- 5Y*
- 6.99%
- 10Y*
- 10.70%
- ALL TIME*
- 8.73%
Liquidity Comparison
| Position | Avg. Volume Value (2W) | Avg. Volume Value (1M) | Avg. Volume Value (3M) |
|---|---|---|---|
| $6.67B | $6.32B | $7.45B | |
| $78.49K | $249.03K | $206.22K |
MID vs. IWM - Yearly Performance Comparison
| 2026 (YTD) | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | |
|---|---|---|---|---|---|---|---|
MID American Century Mid Cap Growth Impact ETF | 2.51% | 8.22% | 19.40% | 22.20% | -27.44% | 10.39% | 30.35% |
IWM iShares Russell 2000 ETF | 18.79% | 12.66% | 11.38% | 16.83% | -20.48% | 14.54% | 39.20% |
Correlation
The correlation between MID and IWM is 0.81, meaning they have usually moved in the same direction, including during past declines.
| Correlation | |
|---|---|
Correlation (1Y) Focuses on recent behavior, but can change the most. | 0.81 |
Correlation (3Y) Balances recent behavior with more history. | 0.82 |
Correlation (5Y) Shows whether the relationship held over a longer period. | 0.84 |
Correlation (All Time) Calculated using the full available price history since Jul 15, 2020 | 0.79 |
The correlation between MID and IWM has been stable across timeframes, ranging from 0.79 to 0.84 - a consistent structural relationship.
MID vs. IWM - Sectors Allocation Comparison
Sectors
MID
IWM
Technology
Industrials
Healthcare
Consumer Cyclical
Energy
Communication Services
Utilities
Financial Services
Basic Materials
Consumer Defensive
Real Estate
-
Technology
MID
IWM
Industrials
MID
IWM
Healthcare
MID
IWM
Consumer Cyclical
MID
IWM
Energy
MID
IWM
Communication Services
MID
IWM
Utilities
MID
IWM
Financial Services
MID
IWM
Basic Materials
MID
IWM
Consumer Defensive
MID
IWM
Real Estate
MID
-
IWM
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Return for Risk
MID vs. IWM — Risk / Return Rank
MID
IWM
MID vs. IWM - Risk-Adjusted Trends Comparison
This table presents a comparison of risk-adjusted performance metrics for American Century Mid Cap Growth Impact ETF (MID) 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.
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.
| MID | IWM | Difference | |
|---|---|---|---|
| Sharpe ratioReturn per unit of total volatility | -1.70 | ||
| Sortino ratioReturn per unit of downside risk | -2.29 | ||
| Omega ratioGain probability vs. loss probability | 1.03 | 1.30 | -0.27 |
| Calmar ratioReturn relative to maximum drawdown | 0.09 | 3.11 | -3.02 |
| Martin ratioReturn relative to average drawdown | 0.26 | 11.02 | -10.75 |
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Drawdowns
MID vs. IWM - Drawdown Comparison
The maximum MID drawdown since its inception was -40.15%, smaller than the maximum IWM drawdown of -59.05%. Use the drawdown chart below to compare losses from any high point for MID and IWM.
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Drawdown Indicators
| MID | IWM | Difference | |
|---|---|---|---|
Max DrawdownLargest peak-to-trough decline | -40.15% | -59.05% | +18.90% |
Max Drawdown (1Y)Largest decline over 1 year | -13.89% | -11.03% | -2.86% |
Max Drawdown (3Y)Largest decline over 3 years | -23.92% | -27.50% | +3.58% |
Max Drawdown (5Y)Largest decline over 5 years | -40.15% | -31.91% | -8.24% |
Max Drawdown (10Y)Largest decline over 10 years | — | -41.13% | — |
Current DrawdownCurrent decline from peak | -4.83% | -3.08% | -1.75% |
Average DrawdownAverage peak-to-trough decline | -13.15% | -10.71% | -2.44% |
Ulcer IndexDepth and duration of drawdowns from previous peaks | 4.83% | 3.11% | +1.72% |
Volatility
MID vs. IWM - Volatility Comparison
American Century Mid Cap Growth Impact ETF (MID) has a higher volatility of 4.75% compared to iShares Russell 2000 ETF (IWM) at 3.82%. This indicates that MID'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.
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Volatility by Period
| MID | IWM | Difference | |
|---|---|---|---|
Volatility (1M)Calculated over the trailing 1-month period | 4.75% | 3.82% | +0.93% |
Volatility (6M)Calculated over the trailing 6-month period | 14.01% | 14.12% | -0.11% |
Volatility (1Y)Calculated over the trailing 1-year period | 17.75% | 19.41% | -1.66% |
Volatility (5Y)Calculated over the trailing 5-year period, annualized | 23.72% | 22.48% | +1.24% |
Volatility (10Y)Calculated over the trailing 10-year period, annualized | 23.80% | 23.01% | +0.79% |
MID vs. IWM - Expense Ratio Comparison
MID has a 0.45% expense ratio, which is higher than IWM's 0.19% expense ratio.
Dividends
MID vs. IWM - Dividend Comparison
MID's dividend yield for the trailing twelve months is around 0.15%, less than IWM's 0.91% yield.
| Position | TTM | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
IWM iShares Russell 2000 ETF | 0.91% | 1.04% | 1.15% | 1.35% | 1.48% | 0.94% | 1.04% | 1.26% | 1.40% | 1.26% | 1.38% | 1.54% |
MID American Century Mid Cap Growth Impact ETF | 0.15% | 0.18% | 0.17% | 0.02% | 0.00% | 0.00% | 0.00% | 0.00% | 0.00% | 0.00% | 0.00% | 0.00% |
Frequently Asked Questions
MID and IWM have a correlation of 0.81, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.
MID has higher volatility (4.75%) compared to IWM (3.82%). In terms of maximum drawdown, MID dropped -40.15% vs IWM's -59.05%.
On 5-year performance, IWM leads with 6.99% vs 2.57% for MID. On fees, IWM is cheaper at 0.19% per year. On volatility, IWM has been the lower-risk option at 3.82%. The better choice depends on whether you care most about return, fees, risk, or income.
Over the 5-year period, IWM has performed better with a 6.99% return vs 2.57%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.
IWM is cheaper with a 0.19% expense ratio, compared with 0.45% for MID.
IWM has the higher dividend yield at 0.91%, compared with 0.15% for MID.
MID is categorized as Mid Cap Growth Equities, while IWM is Small Cap Blend Equities. They also come from different issuers: American Century and iShares. Their fees differ too: 0.45% for MID and 0.19% for IWM.
IWM currently has the higher Sharpe Ratio (1.77 vs 0.07), 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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