VEMPX vs. NMPAX

Last updated Jul 18, 2026

VEMPX (Vanguard Extended Market Index Fund Institutional Plus Shares) and NMPAX (Columbia Mid Cap Index Fund) are both Mid Cap Blend Equities funds. Over the past 10 years, VEMPX returned 11.89%/yr vs 10.43%/yr for NMPAX. With a 0.96 correlation, they move nearly in lockstep. VEMPX charges 0.04%/yr vs 0.20%/yr for NMPAX.

Performance

VEMPX vs. NMPAX - 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 Columbia Mid Cap Index Fund (NMPAX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

The year-to-date returns for both investments are quite close, with VEMPX having a 15.17% return and NMPAX slightly higher at 15.64%. Over the past 10 years, VEMPX has outperformed NMPAX with an annualized return of 11.89%, while NMPAX has yielded a comparatively lower 10.43% annualized return.

VEMPX

• 1D: -0.36%
• 1M: 1.19%
• 6M: 8.84%
• YTD: 15.17%
• 1Y: 22.04%
• 3Y*: 17.13%
• 5Y*: 7.14%
• 10Y*: 11.89%

NMPAX

• 1D: 0.51%
• 1M: 1.42%
• 6M: 8.96%
• YTD: 15.64%
• 1Y: 21.13%
• 3Y*: 13.66%
• 5Y*: 9.23%
• 10Y*: 10.43%

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

VEMPX vs. NMPAX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
VEMPX Vanguard Extended Market Index Fund Institutional Plus Shares	15.17%	11.43%	15.50%	26.98%	-26.45%	12.48%	32.24%	28.06%	-9.35%	18.13%
NMPAX Columbia Mid Cap Index Fund	15.64%	7.23%	13.67%	16.32%	-13.27%	24.66%	8.71%	25.99%	-11.44%	15.84%

Correlation

The correlation between VEMPX and NMPAX is 0.93, 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	0.93
Correlation (3Y) Calculated over the trailing 3-year period	0.95
Correlation (5Y) Calculated over the trailing 5-year period	0.95
Correlation (10Y) Calculated over the trailing 10-year period	0.95
Correlation (All Time) Calculated using the full available price history since Dec 13, 2010	0.96

The correlation between VEMPX and NMPAX has been stable across timeframes, ranging from 0.93 to 0.96 - a consistent structural relationship.

Return for Risk

VEMPX vs. NMPAX — Risk / Return Rank

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

VEMPX

VEMPX Risk / Return Rank: 37
VEMPX Sharpe Ratio Rank: 32
VEMPX Sortino Ratio Rank: 32
VEMPX Omega Ratio Rank: 29
VEMPX Calmar Ratio Rank: 49
VEMPX Martin Ratio Rank: 45

NMPAX

NMPAX Risk / Return Rank: 48
NMPAX Sharpe Ratio Rank: 39
NMPAX Sortino Ratio Rank: 42
NMPAX Omega Ratio Rank: 37
NMPAX Calmar Ratio Rank: 66
NMPAX Martin Ratio Rank: 57

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. NMPAX - 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 Columbia Mid Cap Index Fund (NMPAX). 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	NMPAX	Difference
Sharpe ratio: Return per unit of total volatility	1.33	1.44	-0.11
Sortino ratio: Return per unit of downside risk	1.93	2.14	-0.21
Omega ratio: Gain probability vs. loss probability	1.23	1.26	-0.02
Calmar ratio: Return relative to maximum drawdown	2.30	2.56	-0.26
Martin ratio: Return relative to average drawdown	7.99	9.25	-1.26

VEMPX vs. NMPAX - Sharpe Ratio Comparison

The current VEMPX Sharpe Ratio is 1.33, which is comparable to the NMPAX Sharpe Ratio of 1.44. The chart below compares the historical Sharpe Ratios of VEMPX and NMPAX, 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. NMPAX - Drawdown Comparison

The maximum VEMPX drawdown since its inception was -41.62%, smaller than the maximum NMPAX drawdown of -54.31%. Use the drawdown chart below to compare losses from any high point for VEMPX and NMPAX.

Drawdown Indicators

	VEMPX	NMPAX	Difference
Max Drawdown Largest peak-to-trough decline	-41.62%	-54.31%	+12.69%
Max Drawdown (1Y) Largest decline over 1 year	-10.25%	-8.84%	-1.41%
Max Drawdown (3Y) Largest decline over 3 years	-26.83%	-24.03%	-2.80%
Max Drawdown (5Y) Largest decline over 5 years	-36.32%	-24.03%	-12.29%
Max Drawdown (10Y) Largest decline over 10 years	-41.62%	-42.09%	+0.47%
Current Drawdown Current decline from peak	-2.73%	-1.38%	-1.35%
Average Drawdown Average peak-to-trough decline	-7.92%	-7.69%	-0.23%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.94%	2.44%	+0.50%

Volatility

VEMPX vs. NMPAX - Volatility Comparison

Vanguard Extended Market Index Fund Institutional Plus Shares (VEMPX) has a higher volatility of 3.86% compared to Columbia Mid Cap Index Fund (NMPAX) at 3.48%. This indicates that VEMPX's price experiences larger fluctuations and is considered to be riskier than NMPAX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	VEMPX	NMPAX	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.86%	3.48%	+0.38%
Volatility (6M) Calculated over the trailing 6-month period	13.29%	11.70%	+1.59%
Volatility (1Y) Calculated over the trailing 1-year period	17.71%	15.70%	+2.01%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	22.44%	19.70%	+2.74%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	22.33%	21.06%	+1.27%

VEMPX vs. NMPAX - Expense Ratio Comparison

VEMPX has a 0.04% expense ratio, which is lower than NMPAX's 0.20% expense ratio. Despite the difference, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.

Dividends

VEMPX vs. NMPAX - Dividend Comparison

VEMPX's dividend yield for the trailing twelve months is around 1.03%, less than NMPAX's 10.35% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
NMPAX Columbia Mid Cap Index Fund	10.35%	9.34%	11.35%	7.97%	11.65%	18.03%	5.96%	5.70%	10.06%	7.66%	7.97%	10.12%
VEMPX Vanguard Extended Market Index Fund Institutional Plus Shares	1.03%	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 NMPAX in my portfolio?

With a correlation of 0.93, VEMPX and NMPAX 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, VEMPX or NMPAX?

VEMPX has higher volatility (3.86%) compared to NMPAX (3.48%). In terms of maximum drawdown, VEMPX dropped -41.62% vs NMPAX's -54.31%.

Which has better risk-adjusted returns?

NMPAX currently has the higher Sharpe Ratio (1.44 vs 1.33), 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.