VEMPX vs. TARKX

Last updated Jun 26, 2026

VEMPX (Vanguard Extended Market Index Fund Institutional Plus Shares) and TARKX (Tarkio Fund) are both Mid Cap Blend Equities funds. Over the past 10 years, VEMPX returned 12.59%/yr vs 15.74%/yr for TARKX. Their correlation of 0.87 suggests significant overlap in exposure. VEMPX charges 0.04%/yr vs 1.00%/yr for TARKX.

Performance

VEMPX vs. TARKX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Vanguard Extended Market Index Fund Institutional Plus Shares (VEMPX) and Tarkio Fund (TARKX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, VEMPX achieves a 15.02% return, which is significantly lower than TARKX's 23.23% return. Over the past 10 years, VEMPX has underperformed TARKX with an annualized return of 12.59%, while TARKX has yielded a comparatively higher 15.74% annualized return.

VEMPX

• 1D: 0.35%
• 1M: 2.29%
• YTD: 15.02%
• 6M: 12.45%
• 1Y: 28.10%
• 3Y*: 20.10%
• 5Y*: 6.00%
• 10Y*: 12.59%

TARKX

• 1D: 2.71%
• 1M: -0.18%
• YTD: 23.23%
• 6M: 20.89%
• 1Y: 56.94%
• 3Y*: 28.59%
• 5Y*: 11.12%
• 10Y*: 15.74%

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

VEMPX vs. TARKX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
VEMPX Vanguard Extended Market Index Fund Institutional Plus Shares	15.02%	11.43%	15.50%	26.98%	-26.45%	12.48%	32.24%	28.06%	-9.35%	18.13%
TARKX Tarkio Fund	23.23%	30.18%	21.72%	26.33%	-30.39%	24.41%	27.00%	29.54%	-23.30%	29.04%

Correlation

The correlation between VEMPX and TARKX is 0.77, which is moderate. They share some common price drivers but move independently often enough to provide real diversification benefit when combined.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.77
Correlation (3Y) Calculated over the trailing 3-year period	0.81
Correlation (5Y) Calculated over the trailing 5-year period	0.85
Correlation (10Y) Calculated over the trailing 10-year period	0.85
Correlation (All Time) Calculated using the full available price history since Jun 30, 2011	0.87

The correlation between VEMPX and TARKX has been stable across timeframes, ranging from 0.77 to 0.87 - a consistent structural relationship.

Return for Risk

VEMPX vs. TARKX — Risk / Return Rank

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

VEMPX

VEMPX Risk / Return Rank: 45
VEMPX Sharpe Ratio Rank: 38
VEMPX Sortino Ratio Rank: 37
VEMPX Omega Ratio Rank: 35
VEMPX Calmar Ratio Rank: 62
VEMPX Martin Ratio Rank: 52

TARKX

TARKX Risk / Return Rank: 69
TARKX Sharpe Ratio Rank: 70
TARKX Sortino Ratio Rank: 60
TARKX Omega Ratio Rank: 54
TARKX Calmar Ratio Rank: 83
TARKX Martin Ratio Rank: 78

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.

VEMPX vs. TARKX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Vanguard Extended Market Index Fund Institutional Plus Shares (VEMPX) and Tarkio Fund (TARKX). 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.

	VEMPX	TARKX	Difference
Sharpe ratio: Return per unit of total volatility	1.52	2.01	-0.49
Sortino ratio: Return per unit of downside risk	2.16	2.66	-0.50
Omega ratio: Gain probability vs. loss probability	1.26	1.33	-0.07
Calmar ratio: Return relative to maximum drawdown	2.64	3.36	-0.72
Martin ratio: Return relative to average drawdown	9.26	12.23	-2.98

VEMPX vs. TARKX - Sharpe Ratio Comparison

The current VEMPX Sharpe Ratio is 1.52, which is comparable to the TARKX Sharpe Ratio of 2.01. The chart below compares the historical Sharpe Ratios of VEMPX and TARKX, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Drawdowns

VEMPX vs. TARKX - Drawdown Comparison

The maximum VEMPX drawdown since its inception was -41.62%, roughly equal to the maximum TARKX drawdown of -40.55%. Use the drawdown chart below to compare losses from any high point for VEMPX and TARKX.

Drawdown Indicators

	VEMPX	TARKX	Difference
Max Drawdown Largest peak-to-trough decline	-41.62%	-40.55%	-1.07%
Max Drawdown (1Y) Largest decline over 1 year	-10.25%	-16.99%	+6.74%
Max Drawdown (3Y) Largest decline over 3 years	-26.83%	-36.99%	+10.16%
Max Drawdown (5Y) Largest decline over 5 years	-36.32%	-40.38%	+4.06%
Max Drawdown (10Y) Largest decline over 10 years	-41.62%	-40.55%	-1.07%
Current Drawdown Current decline from peak	-0.71%	-1.21%	+0.50%
Average Drawdown Average peak-to-trough decline	-7.94%	-10.34%	+2.40%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.92%	4.66%	-1.74%

Volatility

VEMPX vs. TARKX - Volatility Comparison

The current volatility for Vanguard Extended Market Index Fund Institutional Plus Shares (VEMPX) is 6.12%, while Tarkio Fund (TARKX) has a volatility of 9.65%. This indicates that VEMPX experiences smaller price fluctuations and is considered to be less risky than TARKX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	VEMPX	TARKX	Difference
Volatility (1M) Calculated over the trailing 1-month period	6.12%	9.65%	-3.53%
Volatility (6M) Calculated over the trailing 6-month period	13.28%	21.84%	-8.56%
Volatility (1Y) Calculated over the trailing 1-year period	17.82%	28.40%	-10.58%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	22.45%	27.73%	-5.28%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	22.37%	26.74%	-4.37%

VEMPX vs. TARKX - Expense Ratio Comparison

VEMPX has a 0.04% expense ratio, which is lower than TARKX's 1.00% expense ratio.

Dividends

VEMPX vs. TARKX - Dividend Comparison

VEMPX's dividend yield for the trailing twelve months is around 1.26%, less than TARKX's 4.46% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
TARKX Tarkio Fund	4.46%	5.50%	1.51%	2.98%	10.62%	1.40%	0.50%	5.21%	3.34%	1.70%	0.47%	0.36%
VEMPX Vanguard Extended Market Index Fund Institutional Plus Shares	1.26%	1.15%	1.11%	1.27%	1.17%	1.15%	1.09%	1.32%	1.68%	1.27%	1.46%	1.39%

Frequently Asked Questions

Can I hold both VEMPX and TARKX in my portfolio?

VEMPX and TARKX have a correlation of 0.77, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, VEMPX or TARKX?

TARKX has higher volatility (9.65%) compared to VEMPX (6.12%). In terms of maximum drawdown, VEMPX dropped -41.62% vs TARKX's -40.55%.

Which has better risk-adjusted returns?

TARKX currently has the higher Sharpe Ratio (2.01 vs 1.52), 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.