VEMIX vs. COBYX

Last updated Aug 4, 2026

VEMIX (Vanguard Emerging Markets Stock Index Fund Institutional Shares) and COBYX (The Cook & Bynum Fund) are both Emerging Markets Equities funds. Over the past 10 years, VEMIX returned 7.82%/yr vs 4.83%/yr for COBYX. Their 0.51 correlation means they have sometimes moved together and sometimes differently. VEMIX charges 0.06%/yr vs 1.49%/yr for COBYX.

Performance

VEMIX vs. COBYX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Vanguard Emerging Markets Stock Index Fund Institutional Shares (VEMIX) and The Cook & Bynum Fund (COBYX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, VEMIX achieves a 9.18% return, which is significantly lower than COBYX's 12.05% return. Over the past 10 years, VEMIX has outperformed COBYX with an annualized return of 7.82%, while COBYX has yielded a comparatively lower 4.83% annualized return.

VEMIX

• 1D: 1.26%
• 1M: -0.48%
• 6M: 3.65%
• YTD: 9.18%
• 1Y: 21.49%
• 3Y*: 14.60%
• 5Y*: 6.08%
• 10Y*: 7.82%
• ALL TIME*: 7.29%

COBYX

• 1D: 0.20%
• 1M: 0.61%
• 6M: 7.82%
• YTD: 12.05%
• 1Y: 20.86%
• 3Y*: 8.07%
• 5Y*: 9.07%
• 10Y*: 4.83%
• ALL TIME*: 4.79%

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

Liquidity Comparison

Position	Avg. Volume Value (2W)	Avg. Volume Value (1M)	Avg. Volume Value (3M)
COBYX The Cook & Bynum Fund	$0.00	$0.00	$0.00
VEMIX Vanguard Emerging Markets Stock Index Fund Institutional Shares	$0.00	$0.00	$0.00

VEMIX vs. COBYX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
VEMIX Vanguard Emerging Markets Stock Index Fund Institutional Shares	9.18%	24.80%	11.38%	8.85%	-17.75%	0.91%	15.26%	20.35%	-14.55%	31.42%
COBYX The Cook & Bynum Fund	12.05%	20.50%	-10.32%	16.73%	9.28%	9.05%	-10.97%	9.40%	-13.40%	15.12%

Correlation

The correlation between VEMIX and COBYX is 0.28, which is low. Their historical price movements had little consistent relationship.

	Correlation
Correlation (1Y) Focuses on recent behavior, but can change the most.	0.28
Correlation (3Y) Balances recent behavior with more history.	0.38
Correlation (5Y) Shows whether the relationship held over a longer period.	0.46
Correlation (10Y) Provides a long-term view across more market conditions.	0.50
Correlation (All Time) Calculated using the full available price history since Jan 2, 2013	0.51

Over the past year, the correlation between VEMIX and COBYX has dropped to 0.28 - well below their long-term average of 0.51, suggesting their price drivers have been diverging.

Return for Risk

VEMIX vs. COBYX — Risk / Return Rank

Compare historical risk-adjusted metric ranks over the past 12 months.

VEMIX

VEMIX Risk / Return Rank: 40
VEMIX Sharpe Ratio Rank: 40
VEMIX Sortino Ratio Rank: 38
VEMIX Omega Ratio Rank: 39
VEMIX Calmar Ratio Rank: 44
VEMIX Martin Ratio Rank: 40

COBYX

COBYX Risk / Return Rank: 70
COBYX Sharpe Ratio Rank: 75
COBYX Sortino Ratio Rank: 75
COBYX Omega Ratio Rank: 72
COBYX Calmar Ratio Rank: 69
COBYX Martin Ratio Rank: 57

The rank (0–100) uses a weighted average of the Sharpe, Sortino, Omega, Calmar, and Martin percentile ranks for the trailing 12 months. Higher means stronger historical risk-adjusted performance within the peer group.

VEMIX vs. COBYX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Vanguard Emerging Markets Stock Index Fund Institutional Shares (VEMIX) and The Cook & Bynum Fund (COBYX). 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.

	VEMIX	COBYX	Difference
Sharpe ratio: Return per unit of total volatility	1.29	1.82	-0.53
Sortino ratio: Return per unit of downside risk	1.82	2.64	-0.82
Omega ratio: Gain probability vs. loss probability	1.23	1.33	-0.10
Calmar ratio: Return relative to maximum drawdown	1.87	2.38	-0.52
Martin ratio: Return relative to average drawdown	6.20	8.07	-1.86

VEMIX vs. COBYX - Sharpe Ratio Comparison

The current VEMIX Sharpe Ratio is 1.29, which is comparable to the COBYX Sharpe Ratio of 1.82. The chart below compares the historical Sharpe Ratios of VEMIX and COBYX, 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

VEMIX vs. COBYX - Drawdown Comparison

The maximum VEMIX drawdown since its inception was -66.43%, which is greater than COBYX's maximum drawdown of -34.18%. Use the drawdown chart below to compare losses from any high point for VEMIX and COBYX.

Drawdown Indicators

	VEMIX	COBYX	Difference
Max Drawdown Largest peak-to-trough decline	-66.43%	-34.18%	-32.25%
Max Drawdown (1Y) Largest decline over 1 year	-11.05%	-8.95%	-2.10%
Max Drawdown (3Y) Largest decline over 3 years	-15.77%	-16.29%	+0.52%
Max Drawdown (5Y) Largest decline over 5 years	-30.68%	-17.10%	-13.58%
Max Drawdown (10Y) Largest decline over 10 years	-36.04%	-34.18%	-1.86%
Current Drawdown Current decline from peak	-4.23%	0.00%	-4.23%
Average Drawdown Average peak-to-trough decline	-15.91%	-6.73%	-9.18%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.32%	2.66%	+0.66%

Volatility

VEMIX vs. COBYX - Volatility Comparison

Vanguard Emerging Markets Stock Index Fund Institutional Shares (VEMIX) has a higher volatility of 5.34% compared to The Cook & Bynum Fund (COBYX) at 3.10%. This indicates that VEMIX's price experiences larger fluctuations and is considered to be riskier than COBYX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	VEMIX	COBYX	Difference
Volatility (1M) Calculated over the trailing 1-month period	5.34%	3.10%	+2.24%
Volatility (6M) Calculated over the trailing 6-month period	13.86%	9.77%	+4.09%
Volatility (1Y) Calculated over the trailing 1-year period	16.03%	11.81%	+4.22%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	15.59%	13.95%	+1.64%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	16.50%	13.67%	+2.83%

VEMIX vs. COBYX - Expense Ratio Comparison

VEMIX has a 0.06% expense ratio, which is lower than COBYX's 1.49% expense ratio.

Dividends

VEMIX vs. COBYX - Dividend Comparison

VEMIX's dividend yield for the trailing twelve months is around 2.35%, more than COBYX's 1.05% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
COBYX The Cook & Bynum Fund	1.05%	1.18%	0.00%	1.01%	1.16%	2.18%	0.32%	0.69%	12.60%	1.88%	5.09%	0.00%
VEMIX Vanguard Emerging Markets Stock Index Fund Institutional Shares	2.35%	2.77%	3.17%	3.51%	4.09%	2.61%	1.90%	3.23%	2.89%	2.33%	2.55%	2.51%

Frequently Asked Questions

Can I hold both VEMIX and COBYX in my portfolio?

VEMIX and COBYX have a correlation of 0.28, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, VEMIX or COBYX?

VEMIX has higher volatility (5.34%) compared to COBYX (3.10%). In terms of maximum drawdown, VEMIX dropped -66.43% vs COBYX's -34.18%.

Which has better risk-adjusted returns?

COBYX currently has the higher Sharpe Ratio (1.82 vs 1.29), 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.