GMCOX vs. SSAFX

Last updated Jun 3, 2026

GMCOX (GuideMark Core Fixed Income Fund) and SSAFX (State Street Aggregate Bond Index Portfolio) are both Intermediate Core Bond funds. Over the past 10 years, GMCOX returned 1.15%/yr vs 27.82%/yr for SSAFX. Their correlation of 0.93 suggests significant overlap in exposure. GMCOX charges 0.95%/yr vs 0.02%/yr for SSAFX.

Performance

GMCOX vs. SSAFX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in GuideMark Core Fixed Income Fund (GMCOX) and State Street Aggregate Bond Index Portfolio (SSAFX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, GMCOX achieves a -0.24% return, which is significantly lower than SSAFX's 0.37% return. Over the past 10 years, GMCOX has underperformed SSAFX with an annualized return of 1.15%, while SSAFX has yielded a comparatively higher 27.82% annualized return.

GMCOX

• 1D: -0.12%
• 1M: -0.12%
• YTD: -0.24%
• 6M: -0.14%
• 1Y: 4.72%
• 3Y*: 3.76%
• 5Y*: -0.37%
• 10Y*: 1.15%

SSAFX

• 1D: -0.09%
• 1M: 0.11%
• YTD: 0.37%
• 6M: 0.42%
• 1Y: 5.32%
• 3Y*: 3.88%
• 5Y*: 0.04%
• 10Y*: 27.82%

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

GMCOX vs. SSAFX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
GMCOX GuideMark Core Fixed Income Fund	-0.24%	6.56%	1.39%	6.19%	-14.64%	-2.01%	8.13%	8.58%	-1.44%	2.81%
SSAFX State Street Aggregate Bond Index Portfolio	0.37%	6.81%	1.34%	5.61%	-13.30%	-1.72%	978.57%	8.69%	-0.12%	3.38%

Correlation

The correlation between GMCOX and SSAFX 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	0.94
Correlation (5Y) Calculated over the trailing 5-year period	0.94
Correlation (10Y) Calculated over the trailing 10-year period	0.93
Correlation (All Time) Calculated using the full available price history since Sep 23, 2014	0.93

The correlation between GMCOX and SSAFX has been stable across timeframes, ranging from 0.93 to 0.94 - a consistent structural relationship.

Return for Risk

GMCOX vs. SSAFX — Risk / Return Rank

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

GMCOX

GMCOX Risk / Return Rank: 16
GMCOX Sharpe Ratio Rank: 16
GMCOX Sortino Ratio Rank: 17
GMCOX Omega Ratio Rank: 15
GMCOX Calmar Ratio Rank: 17
GMCOX Martin Ratio Rank: 16

SSAFX

SSAFX Risk / Return Rank: 22
SSAFX Sharpe Ratio Rank: 21
SSAFX Sortino Ratio Rank: 22
SSAFX Omega Ratio Rank: 19
SSAFX Calmar Ratio Rank: 25
SSAFX Martin Ratio Rank: 22

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.

GMCOX vs. SSAFX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for GuideMark Core Fixed Income Fund (GMCOX) and State Street Aggregate Bond Index Portfolio (SSAFX). 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.

	GMCOX	SSAFX	Difference
Sharpe ratio Return per unit of total volatility	1.15	1.35	-0.20
Sortino ratio Return per unit of downside risk	1.74	2.02	-0.28
Omega ratio Gain probability vs. loss probability	1.20	1.24	-0.04
Calmar ratio Return relative to maximum drawdown	1.51	1.91	-0.41
Martin ratio Return relative to average drawdown	4.54	5.88	-1.34
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

GMCOX vs. SSAFX - Sharpe Ratio Comparison

The current GMCOX Sharpe Ratio is 1.15, which is comparable to the SSAFX Sharpe Ratio of 1.35. The chart below compares the historical Sharpe Ratios of GMCOX and SSAFX, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Sharpe Ratios by Period

	GMCOX	SSAFX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.15	1.35	-0.20
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	-0.06	0.01	-0.07
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.23	0.10	+0.13
Sharpe Ratio (All Time) Calculated using the full available price history	0.14	0.09	+0.05

Drawdowns

GMCOX vs. SSAFX - Drawdown Comparison

The maximum GMCOX drawdown since its inception was -28.49%, which is greater than SSAFX's maximum drawdown of -18.74%. Use the drawdown chart below to compare losses from any high point for GMCOX and SSAFX.

Drawdown Indicators

	GMCOX	SSAFX	Difference
Max Drawdown Largest peak-to-trough decline	-28.49%	-18.74%	-9.75%
Max Drawdown (1Y) Largest decline over 1 year	-2.96%	-2.74%	-0.22%
Max Drawdown (3Y) Largest decline over 3 years	-6.46%	-6.09%	-0.37%
Max Drawdown (5Y) Largest decline over 5 years	-19.75%	-18.10%	-1.65%
Max Drawdown (10Y) Largest decline over 10 years	-20.36%	-18.74%	-1.62%
Current Drawdown Current decline from peak	-4.50%	-2.66%	-1.84%
Average Drawdown Average peak-to-trough decline	-7.81%	-4.41%	-3.40%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.98%	0.89%	+0.09%

Volatility

GMCOX vs. SSAFX - Volatility Comparison

GuideMark Core Fixed Income Fund (GMCOX) has a higher volatility of 1.39% compared to State Street Aggregate Bond Index Portfolio (SSAFX) at 1.30%. This indicates that GMCOX's price experiences larger fluctuations and is considered to be riskier than SSAFX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	GMCOX	SSAFX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.39%	1.30%	+0.09%
Volatility (6M) Calculated over the trailing 6-month period	2.72%	2.66%	+0.06%
Volatility (1Y) Calculated over the trailing 1-year period	3.90%	3.75%	+0.15%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	5.94%	5.95%	-0.01%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	4.98%	277.51%	-272.53%

GMCOX vs. SSAFX - Expense Ratio Comparison

GMCOX has a 0.95% expense ratio, which is higher than SSAFX's 0.02% expense ratio.

Dividends

GMCOX vs. SSAFX - Dividend Comparison

GMCOX's dividend yield for the trailing twelve months is around 3.54%, less than SSAFX's 4.17% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
GMCOX GuideMark Core Fixed Income Fund	3.54%	3.54%	3.39%	3.40%	2.27%	2.16%	3.49%	1.45%	2.38%	2.35%	2.29%	2.55%
SSAFX State Street Aggregate Bond Index Portfolio	4.17%	3.70%	3.76%	3.16%	2.49%	1.90%	2.41%	2.88%	2.82%	2.42%	2.21%	3.21%

Frequently Asked Questions

Can I hold both GMCOX and SSAFX in my portfolio?

With a correlation of 0.93, GMCOX and SSAFX 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, GMCOX or SSAFX?

GMCOX has higher volatility (1.39%) compared to SSAFX (1.30%). In terms of maximum drawdown, GMCOX dropped -28.49% vs SSAFX's -18.74%.

Which has better risk-adjusted returns?

SSAFX currently has the higher Sharpe Ratio (1.35 vs 1.15), 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.