UNG vs. IWM
UNG (United States Natural Gas Fund LP) and IWM (iShares Russell 2000 ETF) are both exchange-traded funds - UNG is a Oil & Gas fund tracking the Front Month Natural Gas Futures, while IWM is a Small Cap Blend Equities fund tracking the Russell 2000 Index. Both are passively managed. Over the past 10 years, UNG returned -22.45%/yr vs 10.65%/yr for IWM. At a 0.04 correlation, their price movements are largely independent. UNG charges 1.17%/yr vs 0.19%/yr for IWM.
Performance
UNG vs. IWM - Performance Comparison
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Returns By Period
In the year-to-date period, UNG achieves a -16.07% return, which is significantly lower than IWM's 19.24% return. Over the past 10 years, UNG has underperformed IWM with an annualized return of -22.45%, while IWM has yielded a comparatively higher 10.65% annualized return.
UNG
- 1D
- -2.09%
- 1M
- -12.35%
- 6M
- -0.39%
- YTD
- -16.07%
- 1Y
- -35.08%
- 3Y*
- -29.27%
- 5Y*
- -28.40%
- 10Y*
- -22.45%
- ALL TIME*
- -28.43%
IWM
- 1D
- -0.59%
- 1M
- -1.11%
- 6M
- 10.45%
- YTD
- 19.24%
- 1Y
- 32.84%
- 3Y*
- 15.91%
- 5Y*
- 6.97%
- 10Y*
- 10.65%
- ALL TIME*
- 8.76%
UNG vs. IWM - Yearly Performance Comparison
| 2026 (YTD) | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | |
|---|---|---|---|---|---|---|---|---|---|---|
UNG United States Natural Gas Fund LP | -16.07% | -27.07% | -17.11% | -64.04% | 12.89% | 35.76% | -45.43% | -31.77% | 5.96% | -37.58% |
IWM iShares Russell 2000 ETF | 19.24% | 12.66% | 11.38% | 16.83% | -20.48% | 14.54% | 20.03% | 25.39% | -11.12% | 14.58% |
Correlation
The correlation between UNG and IWM is -0.25, 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 | -0.25 |
Correlation (3Y) Calculated over the trailing 3-year period | -0.06 |
Correlation (5Y) Calculated over the trailing 5-year period | 0.03 |
Correlation (10Y) Calculated over the trailing 10-year period | 0.04 |
Correlation (All Time) Calculated using the full available price history since Apr 18, 2007 | 0.04 |
The correlation between UNG and IWM shifts across timeframes, from -0.25 (1 year) to 0.04 (all time), reflecting how their relationship changes across market environments.
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Return for Risk
UNG vs. IWM — Risk / Return Rank
UNG
IWM
UNG vs. IWM - Risk-Adjusted Trends Comparison
This table presents a comparison of risk-adjusted performance metrics for United States Natural Gas Fund LP (UNG) 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.
| UNG | IWM | Difference | |
|---|---|---|---|
| Sharpe ratioReturn per unit of total volatility | -2.30 | ||
| Sortino ratioReturn per unit of downside risk | -3.01 | ||
| Omega ratioGain probability vs. loss probability | 0.93 | 1.29 | -0.36 |
| Calmar ratioReturn relative to maximum drawdown | -0.88 | 2.99 | -3.87 |
| Martin ratioReturn relative to average drawdown | -1.42 | 10.54 | -11.97 |
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Drawdowns
UNG vs. IWM - Drawdown Comparison
The maximum UNG drawdown since its inception was -99.88%, which is greater than IWM's maximum drawdown of -59.05%. Use the drawdown chart below to compare losses from any high point for UNG and IWM.
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Drawdown Indicators
| UNG | IWM | Difference | |
|---|---|---|---|
Max DrawdownLargest peak-to-trough decline | -99.88% | -59.05% | -40.83% |
Max Drawdown (1Y)Largest decline over 1 year | -39.94% | -11.03% | -28.91% |
Max Drawdown (3Y)Largest decline over 3 years | -68.16% | -27.50% | -40.66% |
Max Drawdown (5Y)Largest decline over 5 years | -92.49% | -31.91% | -60.58% |
Max Drawdown (10Y)Largest decline over 10 years | -93.55% | -41.13% | -52.42% |
Current DrawdownCurrent decline from peak | -99.87% | -2.71% | -97.16% |
Average DrawdownAverage peak-to-trough decline | -90.01% | -10.72% | -79.29% |
Ulcer IndexDepth and duration of drawdowns from previous peaks | 25.99% | 3.12% | +22.87% |
Volatility
UNG vs. IWM - Volatility Comparison
United States Natural Gas Fund LP (UNG) has a higher volatility of 10.17% compared to iShares Russell 2000 ETF (IWM) at 3.62%. This indicates that UNG'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
| UNG | IWM | Difference | |
|---|---|---|---|
Volatility (1M)Calculated over the trailing 1-month period | 10.17% | 3.62% | +6.55% |
Volatility (6M)Calculated over the trailing 6-month period | 47.34% | 14.17% | +33.17% |
Volatility (1Y)Calculated over the trailing 1-year period | 59.71% | 19.38% | +40.33% |
Volatility (5Y)Calculated over the trailing 5-year period, annualized | 64.17% | 22.49% | +41.68% |
Volatility (10Y)Calculated over the trailing 10-year period, annualized | 54.76% | 23.00% | +31.76% |
UNG vs. IWM - Expense Ratio Comparison
UNG has a 1.17% expense ratio, which is higher than IWM's 0.19% expense ratio.
Dividends
UNG vs. IWM - Dividend Comparison
UNG has not paid dividends to shareholders, while IWM's dividend yield for the trailing twelve months is around 0.91%.
| 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% |
UNG United States Natural Gas Fund LP | 0.00% | 0.00% | 0.00% | 0.00% | 0.00% | 0.00% | 0.00% | 0.00% | 0.00% | 0.00% | 0.00% | 0.00% |
Frequently Asked Questions
UNG and IWM have a correlation of -0.25, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.
UNG has higher volatility (10.17%) compared to IWM (3.62%). In terms of maximum drawdown, UNG dropped -99.88% vs IWM's -59.05%.
On 10-year performance, IWM leads with 10.65% vs -22.45% for UNG. On fees, IWM is cheaper at 0.19% per year. On volatility, IWM has been the lower-risk option at 3.62%. The better choice depends on whether you care most about return, fees, risk, or income.
Over the 10-year period, IWM has performed better with a 10.65% return vs -22.45%. 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 1.17% for UNG.
IWM has the higher dividend yield at 0.91%, compared with 0.00% for UNG.
UNG is categorized as Oil & Gas, while IWM is Small Cap Blend Equities. UNG tracks Front Month Natural Gas Futures, while IWM tracks Russell 2000 Index. They also come from different issuers: USCF Investments and iShares. Their fees differ too: 1.17% for UNG and 0.19% for IWM.
IWM currently has the higher Sharpe Ratio (1.71 vs -0.59), 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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