GASFX vs. VIMAX

Last updated Jun 4, 2026

GASFX (Hennessy Gas Utility Fund) and VIMAX (Vanguard Mid-Cap Index Fund Admiral Shares) are both mutual funds - GASFX is a Utilities Equities fund managed by Hennessy, while VIMAX is a Mid Cap Blend Equities fund managed by Vanguard. Over the past 10 years, GASFX returned 9.17%/yr vs 11.58%/yr for VIMAX. A 0.67 correlation means they provide meaningful diversification when combined. GASFX charges 1.00%/yr vs 0.05%/yr for VIMAX.

Performance

GASFX vs. VIMAX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Hennessy Gas Utility Fund (GASFX) and Vanguard Mid-Cap Index Fund Admiral Shares (VIMAX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, GASFX achieves a 9.02% return, which is significantly lower than VIMAX's 10.54% return. Over the past 10 years, GASFX has underperformed VIMAX with an annualized return of 9.17%, while VIMAX has yielded a comparatively higher 11.58% annualized return.

GASFX

• 1D: 1.66%
• 1M: -4.14%
• YTD: 9.02%
• 6M: 7.50%
• 1Y: 11.12%
• 3Y*: 15.68%
• 5Y*: 12.33%
• 10Y*: 9.17%

VIMAX

• 1D: 0.90%
• 1M: 3.68%
• YTD: 10.54%
• 6M: 10.20%
• 1Y: 18.73%
• 3Y*: 16.82%
• 5Y*: 8.10%
• 10Y*: 11.58%

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

GASFX vs. VIMAX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
GASFX Hennessy Gas Utility Fund	9.02%	10.42%	24.98%	0.27%	13.68%	19.60%	-9.34%	20.80%	-3.47%	7.04%
VIMAX Vanguard Mid-Cap Index Fund Admiral Shares	10.54%	11.67%	14.66%	16.53%	-18.70%	24.51%	18.18%	31.03%	-9.24%	19.26%

Correlation

The correlation between GASFX and VIMAX is 0.25, which is low. Their price movements are largely independent, making them effective diversification partners.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.25
Correlation (3Y) Calculated over the trailing 3-year period	0.47
Correlation (5Y) Calculated over the trailing 5-year period	0.53
Correlation (10Y) Calculated over the trailing 10-year period	0.53
Correlation (All Time) Calculated using the full available price history since Nov 13, 2001	0.67

Over the past year, the correlation between GASFX and VIMAX has dropped to 0.25 - well below their long-term average of 0.67, suggesting their price drivers have been diverging.

Return for Risk

GASFX vs. VIMAX — Risk / Return Rank

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

GASFX

GASFX Risk / Return Rank: 14
GASFX Sharpe Ratio Rank: 12
GASFX Sortino Ratio Rank: 12
GASFX Omega Ratio Rank: 11
GASFX Calmar Ratio Rank: 19
GASFX Martin Ratio Rank: 18

VIMAX

VIMAX Risk / Return Rank: 35
VIMAX Sharpe Ratio Rank: 32
VIMAX Sortino Ratio Rank: 31
VIMAX Omega Ratio Rank: 29
VIMAX Calmar Ratio Rank: 41
VIMAX Martin Ratio Rank: 44

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.

GASFX vs. VIMAX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Hennessy Gas Utility Fund (GASFX) and Vanguard Mid-Cap Index Fund Admiral Shares (VIMAX). 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.

	GASFX	VIMAX	Difference
Sharpe ratio: Return per unit of total volatility	0.94	1.61	-0.67
Sortino ratio: Return per unit of downside risk	1.38	2.31	-0.93
Omega ratio: Gain probability vs. loss probability	1.16	1.28	-0.12
Calmar ratio: Return relative to maximum drawdown	1.60	2.44	-0.84
Martin ratio: Return relative to average drawdown	4.93	9.28	-4.35
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

GASFX vs. VIMAX - Sharpe Ratio Comparison

The current GASFX Sharpe Ratio is 0.94, which is lower than the VIMAX Sharpe Ratio of 1.61. The chart below compares the historical Sharpe Ratios of GASFX and VIMAX, 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

	GASFX	VIMAX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	0.94	1.61	-0.67
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.80	0.46	+0.34
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.52	0.61	-0.09
Sharpe Ratio (All Time) Calculated using the full available price history	0.57	0.50	+0.06

Drawdowns

GASFX vs. VIMAX - Drawdown Comparison

The maximum GASFX drawdown since its inception was -49.33%, smaller than the maximum VIMAX drawdown of -58.88%. Use the drawdown chart below to compare losses from any high point for GASFX and VIMAX.

Drawdown Indicators

	GASFX	VIMAX	Difference
Max Drawdown Largest peak-to-trough decline	-49.33%	-58.88%	+9.55%
Max Drawdown (1Y) Largest decline over 1 year	-6.95%	-8.13%	+1.18%
Max Drawdown (3Y) Largest decline over 3 years	-12.43%	-18.93%	+6.50%
Max Drawdown (5Y) Largest decline over 5 years	-18.25%	-27.55%	+9.30%
Max Drawdown (10Y) Largest decline over 10 years	-37.23%	-39.30%	+2.07%
Current Drawdown Current decline from peak	-5.41%	0.00%	-5.41%
Average Drawdown Average peak-to-trough decline	-7.86%	-8.12%	+0.26%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.26%	2.14%	+0.12%

Volatility

GASFX vs. VIMAX - Volatility Comparison

Hennessy Gas Utility Fund (GASFX) has a higher volatility of 4.71% compared to Vanguard Mid-Cap Index Fund Admiral Shares (VIMAX) at 2.97%. This indicates that GASFX's price experiences larger fluctuations and is considered to be riskier than VIMAX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	GASFX	VIMAX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.71%	2.97%	+1.74%
Volatility (6M) Calculated over the trailing 6-month period	9.18%	9.28%	-0.10%
Volatility (1Y) Calculated over the trailing 1-year period	11.83%	12.30%	-0.47%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	15.47%	17.63%	-2.16%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	17.68%	18.92%	-1.24%

GASFX vs. VIMAX - Expense Ratio Comparison

GASFX has a 1.00% expense ratio, which is higher than VIMAX's 0.05% expense ratio.

Dividends

GASFX vs. VIMAX - Dividend Comparison

GASFX's dividend yield for the trailing twelve months is around 11.13%, more than VIMAX's 1.34% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
GASFX Hennessy Gas Utility Fund	11.13%	12.06%	7.36%	6.63%	15.49%	10.63%	10.93%	7.11%	12.31%	2.96%	3.52%	5.64%
VIMAX Vanguard Mid-Cap Index Fund Admiral Shares	1.34%	1.51%	1.48%	1.50%	1.59%	1.11%	1.44%	1.47%	1.82%	1.35%	1.45%	1.47%

Frequently Asked Questions

Can I hold both GASFX and VIMAX in my portfolio?

GASFX and VIMAX 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.

Which is riskier, GASFX or VIMAX?

GASFX has higher volatility (4.71%) compared to VIMAX (2.97%). In terms of maximum drawdown, GASFX dropped -49.33% vs VIMAX's -58.88%.

Which has better risk-adjusted returns?

VIMAX currently has the higher Sharpe Ratio (1.61 vs 0.94), 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.