COBYX vs. XLF

Last updated Jun 23, 2026

COBYX (The Cook & Bynum Fund) and XLF (State Street Financial Select Sector SPDR ETF) are both funds - COBYX is a Emerging Markets Diversified fund managed by Cook & Bynum, while XLF is a Financials Equities fund tracking the Financial Select Sector Index. Over the past 10 years, COBYX returned 4.64%/yr vs 13.68%/yr for XLF. A 0.56 correlation means they provide meaningful diversification when combined. COBYX charges 1.49%/yr vs 0.08%/yr for XLF.

Performance

COBYX vs. XLF - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in The Cook & Bynum Fund (COBYX) and State Street Financial Select Sector SPDR ETF (XLF). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, COBYX achieves a 9.37% return, which is significantly higher than XLF's -1.10% return. Over the past 10 years, COBYX has underperformed XLF with an annualized return of 4.64%, while XLF has yielded a comparatively higher 13.68% annualized return.

COBYX

• 1D: -1.13%
• 1M: -1.99%
• YTD: 9.37%
• 6M: 9.19%
• 1Y: 14.99%
• 3Y*: 6.69%
• 5Y*: 8.29%
• 10Y*: 4.64%

XLF

• 1D: 0.59%
• 1M: 3.75%
• YTD: -1.10%
• 6M: -2.09%
• 1Y: 8.66%
• 3Y*: 19.81%
• 5Y*: 10.20%
• 10Y*: 13.68%

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

COBYX vs. XLF - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
COBYX The Cook & Bynum Fund	9.37%	20.50%	-10.32%	16.73%	9.28%	9.05%	-10.97%	9.40%	-13.40%	15.12%
XLF State Street Financial Select Sector SPDR ETF	-1.10%	14.90%	30.56%	12.03%	-10.59%	34.80%	-1.74%	31.88%	-13.06%	22.00%

Correlation

The correlation between COBYX and XLF is 0.37, which is low. Their price movements are largely independent, making them effective diversification partners.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.37
Correlation (3Y) Calculated over the trailing 3-year period	0.42
Correlation (5Y) Calculated over the trailing 5-year period	0.54
Correlation (10Y) Calculated over the trailing 10-year period	0.54
Correlation (All Time) Calculated using the full available price history since Jan 2, 2013	0.56

The correlation between COBYX and XLF shifts across timeframes, from 0.37 (1 year) to 0.56 (all time), reflecting how their relationship changes across market environments.

Return for Risk

COBYX vs. XLF — Risk / Return Rank

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

COBYX

COBYX Risk / Return Rank: 25
COBYX Sharpe Ratio Rank: 24
COBYX Sortino Ratio Rank: 26
COBYX Omega Ratio Rank: 23
COBYX Calmar Ratio Rank: 25
COBYX Martin Ratio Rank: 26

XLF

XLF Risk / Return Rank: 16
XLF Sharpe Ratio Rank: 18
XLF Sortino Ratio Rank: 16
XLF Omega Ratio Rank: 16
XLF Calmar Ratio Rank: 15
XLF Martin Ratio Rank: 15

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.

COBYX vs. XLF - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for The Cook & Bynum Fund (COBYX) and State Street Financial Select Sector SPDR ETF (XLF). 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	XLF	Difference
Sharpe ratio: Return per unit of total volatility	1.32	0.60	+0.72
Sortino ratio: Return per unit of downside risk	1.96	0.89	+1.07
Omega ratio: Gain probability vs. loss probability	1.24	1.11	+0.13
Calmar ratio: Return relative to maximum drawdown	1.75	0.59	+1.16
Martin ratio: Return relative to average drawdown	5.63	1.50	+4.13

COBYX vs. XLF - Sharpe Ratio Comparison

The current COBYX Sharpe Ratio is 1.32, which is higher than the XLF Sharpe Ratio of 0.60. The chart below compares the historical Sharpe Ratios of COBYX and XLF, 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. XLF - Drawdown Comparison

The maximum COBYX drawdown since its inception was -34.18%, smaller than the maximum XLF drawdown of -82.69%. Use the drawdown chart below to compare losses from any high point for COBYX and XLF.

Drawdown Indicators

	COBYX	XLF	Difference
Max Drawdown Largest peak-to-trough decline	-34.18%	-82.69%	+48.51%
Max Drawdown (1Y) Largest decline over 1 year	-8.95%	-14.79%	+5.84%
Max Drawdown (3Y) Largest decline over 3 years	-16.29%	-15.54%	-0.75%
Max Drawdown (5Y) Largest decline over 5 years	-17.10%	-25.81%	+8.71%
Max Drawdown (10Y) Largest decline over 10 years	-34.18%	-42.86%	+8.68%
Current Drawdown Current decline from peak	-2.33%	-3.96%	+1.63%
Average Drawdown Average peak-to-trough decline	-6.78%	-20.00%	+13.22%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.79%	5.78%	-2.99%

Volatility

COBYX vs. XLF - Volatility Comparison

The current volatility for The Cook & Bynum Fund (COBYX) is 3.04%, while State Street Financial Select Sector SPDR ETF (XLF) has a volatility of 4.12%. This indicates that COBYX experiences smaller price fluctuations and is considered to be less risky than XLF based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	COBYX	XLF	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.04%	4.12%	-1.08%
Volatility (6M) Calculated over the trailing 6-month period	9.54%	11.27%	-1.73%
Volatility (1Y) Calculated over the trailing 1-year period	11.90%	14.64%	-2.74%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	13.99%	18.58%	-4.59%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	13.65%	22.18%	-8.53%

COBYX vs. XLF - Expense Ratio Comparison

COBYX has a 1.49% expense ratio, which is higher than XLF's 0.08% expense ratio.

Dividends

COBYX vs. XLF - Dividend Comparison

COBYX's dividend yield for the trailing twelve months is around 1.08%, less than XLF's 1.82% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
COBYX The Cook & Bynum Fund	1.08%	1.18%	0.00%	1.01%	1.16%	2.18%	0.32%	0.69%	12.60%	1.88%	5.09%	0.00%
XLF State Street Financial Select Sector SPDR ETF	1.82%	1.31%	1.42%	1.71%	2.04%	1.63%	2.03%	1.87%	2.08%	1.48%	21.10%	1.95%

Frequently Asked Questions

Can I hold both COBYX and XLF in my portfolio?

COBYX and XLF have a correlation of 0.37, 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 XLF?

XLF has higher volatility (4.12%) compared to COBYX (3.04%). In terms of maximum drawdown, COBYX dropped -34.18% vs XLF's -82.69%.

Which has better risk-adjusted returns?

COBYX currently has the higher Sharpe Ratio (1.32 vs 0.59), 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.