COBYX vs. VEMIX

Last updated Aug 5, 2026

COBYX (The Cook & Bynum Fund) and VEMIX (Vanguard Emerging Markets Stock Index Fund Institutional Shares) are both Emerging Markets Equities funds. Over the past 10 years, COBYX returned 4.67%/yr vs 7.72%/yr for VEMIX. Their 0.51 correlation means they have sometimes moved together and sometimes differently. COBYX charges 1.49%/yr vs 0.06%/yr for VEMIX.

Performance

COBYX vs. VEMIX - Performance Comparison

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

Returns By Period

In the year-to-date period, COBYX achieves a 11.36% return, which is significantly higher than VEMIX's 10.30% return. Over the past 10 years, COBYX has underperformed VEMIX with an annualized return of 4.67%, while VEMIX has yielded a comparatively higher 7.72% annualized return.

COBYX

• 1D: -0.61%
• 1M: 0.00%
• 6M: 4.42%
• YTD: 11.36%
• 1Y: 20.57%
• 3Y*: 8.21%
• 5Y*: 9.23%
• 10Y*: 4.67%
• ALL TIME*: 4.74%

VEMIX

• 1D: 1.03%
• 1M: 0.54%
• 6M: 4.16%
• YTD: 10.30%
• 1Y: 21.34%
• 3Y*: 15.70%
• 5Y*: 5.94%
• 10Y*: 7.72%
• ALL TIME*: 7.33%

*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

COBYX vs. VEMIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
COBYX The Cook & Bynum Fund	11.36%	20.50%	-10.32%	16.73%	9.28%	9.05%	-10.97%	9.40%	-13.40%	15.12%
VEMIX Vanguard Emerging Markets Stock Index Fund Institutional Shares	10.30%	24.80%	11.38%	8.85%	-17.75%	0.91%	15.26%	20.35%	-14.55%	31.42%

Correlation

The correlation between COBYX and VEMIX is 0.27, which is low. Their historical price movements had little consistent relationship.

	Correlation
Correlation (1Y) Focuses on recent behavior, but can change the most.	0.27
Correlation (3Y) Balances recent behavior with more history.	0.37
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 COBYX and VEMIX has dropped to 0.27 - well below their long-term average of 0.51, suggesting their price drivers have been diverging.

Return for Risk

COBYX vs. VEMIX — Risk / Return Rank

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

COBYX

COBYX Risk / Return Rank: 62
COBYX Sharpe Ratio Rank: 67
COBYX Sortino Ratio Rank: 69
COBYX Omega Ratio Rank: 63
COBYX Calmar Ratio Rank: 60
COBYX Martin Ratio Rank: 51

VEMIX

VEMIX Risk / Return Rank: 45
VEMIX Sharpe Ratio Rank: 45
VEMIX Sortino Ratio Rank: 42
VEMIX Omega Ratio Rank: 43
VEMIX Calmar Ratio Rank: 51
VEMIX Martin Ratio Rank: 45

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.

COBYX vs. VEMIX - Risk-Adjusted Trends Comparison

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

	COBYX	VEMIX	Difference
Sharpe ratio: Return per unit of total volatility	1.75	1.43	+0.32
Sortino ratio: Return per unit of downside risk	2.54	1.99	+0.55
Omega ratio: Gain probability vs. loss probability	1.32	1.26	+0.06
Calmar ratio: Return relative to maximum drawdown	2.29	2.07	+0.22
Martin ratio: Return relative to average drawdown	7.76	6.86	+0.90

COBYX vs. VEMIX - Sharpe Ratio Comparison

The current COBYX Sharpe Ratio is 1.75, which is comparable to the VEMIX Sharpe Ratio of 1.43. The chart below compares the historical Sharpe Ratios of COBYX and VEMIX, 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

COBYX vs. VEMIX - Drawdown Comparison

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

Drawdown Indicators

	COBYX	VEMIX	Difference
Max Drawdown Largest peak-to-trough decline	-34.18%	-66.43%	+32.25%
Max Drawdown (1Y) Largest decline over 1 year	-8.95%	-11.05%	+2.10%
Max Drawdown (3Y) Largest decline over 3 years	-16.29%	-15.77%	-0.52%
Max Drawdown (5Y) Largest decline over 5 years	-17.10%	-30.68%	+13.58%
Max Drawdown (10Y) Largest decline over 10 years	-34.18%	-36.04%	+1.86%
Current Drawdown Current decline from peak	-0.61%	-3.25%	+2.64%
Average Drawdown Average peak-to-trough decline	-6.73%	-15.91%	+9.18%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.63%	3.32%	-0.69%

Volatility

COBYX vs. VEMIX - Volatility Comparison

The current volatility for The Cook & Bynum Fund (COBYX) is 3.12%, while Vanguard Emerging Markets Stock Index Fund Institutional Shares (VEMIX) has a volatility of 5.42%. This indicates that COBYX experiences smaller price fluctuations and is considered to be less risky than VEMIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	COBYX	VEMIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.12%	5.42%	-2.30%
Volatility (6M) Calculated over the trailing 6-month period	9.79%	13.75%	-3.96%
Volatility (1Y) Calculated over the trailing 1-year period	11.73%	16.05%	-4.32%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	13.96%	15.60%	-1.64%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	13.68%	16.51%	-2.83%

COBYX vs. VEMIX - Expense Ratio Comparison

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

Dividends

COBYX vs. VEMIX - Dividend Comparison

COBYX's dividend yield for the trailing twelve months is around 1.06%, less than VEMIX's 2.33% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
COBYX The Cook & Bynum Fund	1.06%	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	2.33%	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 COBYX and VEMIX in my portfolio?

COBYX and VEMIX have a correlation of 0.27, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, COBYX or VEMIX?

VEMIX has higher volatility (5.42%) compared to COBYX (3.12%). In terms of maximum drawdown, COBYX dropped -34.18% vs VEMIX's -66.43%.

Which has better risk-adjusted returns?

COBYX currently has the higher Sharpe Ratio (1.75 vs 1.43), 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.