SSAFX vs. VBTLX

Last updated Jun 24, 2026

SSAFX (State Street Aggregate Bond Index Portfolio) and VBTLX (Vanguard Total Bond Market Index Fund Admiral Shares) are both mutual funds - SSAFX is a Intermediate Core Bond fund managed by State Street, while VBTLX is a Total Bond Market fund tracking the Bloomberg U.S. Aggregate Float Adjusted Index. Over the past 10 years, SSAFX returned 27.74%/yr vs 1.50%/yr for VBTLX. Their correlation of 0.93 suggests significant overlap in exposure. SSAFX charges 0.02%/yr vs 0.04%/yr for VBTLX.

Performance

SSAFX vs. VBTLX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in State Street Aggregate Bond Index Portfolio (SSAFX) and Vanguard Total Bond Market Index Fund Admiral Shares (VBTLX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, SSAFX achieves a 0.33% return, which is significantly higher than VBTLX's 0.11% return. Over the past 10 years, SSAFX has outperformed VBTLX with an annualized return of 27.74%, while VBTLX has yielded a comparatively lower 1.50% annualized return.

SSAFX

• 1D: -0.29%
• 1M: 0.60%
• YTD: 0.33%
• 6M: 0.47%
• 1Y: 4.23%
• 3Y*: 3.80%
• 5Y*: -0.06%
• 10Y*: 27.74%

VBTLX

• 1D: -0.31%
• 1M: 0.66%
• YTD: 0.11%
• 6M: 0.45%
• 1Y: 4.14%
• 3Y*: 3.94%
• 5Y*: 0.02%
• 10Y*: 1.50%

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

SSAFX vs. VBTLX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
SSAFX State Street Aggregate Bond Index Portfolio	0.33%	6.81%	1.34%	5.61%	-13.30%	-1.72%	978.57%	8.69%	-0.12%	3.38%
VBTLX Vanguard Total Bond Market Index Fund Admiral Shares	0.11%	7.17%	1.26%	5.74%	-13.16%	-1.81%	7.72%	8.73%	-0.25%	3.56%

Correlation

The correlation between SSAFX and VBTLX is 0.92, 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	0.92
Correlation (3Y) Calculated over the trailing 3-year period	0.95
Correlation (5Y) Calculated over the trailing 5-year period	0.96
Correlation (10Y) Calculated over the trailing 10-year period	0.94
Correlation (All Time) Calculated using the full available price history since Sep 22, 2014	0.93

The correlation between SSAFX and VBTLX has been stable across timeframes, ranging from 0.92 to 0.96 - a consistent structural relationship.

Return for Risk

SSAFX vs. VBTLX — Risk / Return Rank

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

SSAFX

SSAFX Risk / Return Rank: 21
SSAFX Sharpe Ratio Rank: 21
SSAFX Sortino Ratio Rank: 22
SSAFX Omega Ratio Rank: 19
SSAFX Calmar Ratio Rank: 23
SSAFX Martin Ratio Rank: 20

VBTLX

VBTLX Risk / Return Rank: 18
VBTLX Sharpe Ratio Rank: 17
VBTLX Sortino Ratio Rank: 19
VBTLX Omega Ratio Rank: 16
VBTLX Calmar Ratio Rank: 20
VBTLX Martin Ratio Rank: 17

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.

SSAFX vs. VBTLX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for State Street Aggregate Bond Index Portfolio (SSAFX) and Vanguard Total Bond Market Index Fund Admiral Shares (VBTLX). 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.

	SSAFX	VBTLX	Difference
Sharpe ratio: Return per unit of total volatility	1.21	1.12	+0.09
Sortino ratio: Return per unit of downside risk	1.82	1.68	+0.14
Omega ratio: Gain probability vs. loss probability	1.21	1.20	+0.02
Calmar ratio: Return relative to maximum drawdown	1.63	1.51	+0.12
Martin ratio: Return relative to average drawdown	4.67	4.28	+0.38

SSAFX vs. VBTLX - Sharpe Ratio Comparison

The current SSAFX Sharpe Ratio is 1.21, which is comparable to the VBTLX Sharpe Ratio of 1.12. The chart below compares the historical Sharpe Ratios of SSAFX and VBTLX, 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

SSAFX vs. VBTLX - Drawdown Comparison

The maximum SSAFX drawdown since its inception was -18.74%, roughly equal to the maximum VBTLX drawdown of -18.81%. Use the drawdown chart below to compare losses from any high point for SSAFX and VBTLX.

Drawdown Indicators

	SSAFX	VBTLX	Difference
Max Drawdown Largest peak-to-trough decline	-18.74%	-18.81%	+0.07%
Max Drawdown (1Y) Largest decline over 1 year	-2.74%	-2.89%	+0.15%
Max Drawdown (3Y) Largest decline over 3 years	-6.09%	-6.00%	-0.09%
Max Drawdown (5Y) Largest decline over 5 years	-18.10%	-18.14%	+0.04%
Max Drawdown (10Y) Largest decline over 10 years	-18.74%	-18.81%	+0.07%
Current Drawdown Current decline from peak	-2.71%	-2.48%	-0.23%
Average Drawdown Average peak-to-trough decline	-4.40%	-2.67%	-1.73%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.96%	1.02%	-0.06%

Volatility

SSAFX vs. VBTLX - Volatility Comparison

The current volatility for State Street Aggregate Bond Index Portfolio (SSAFX) is 1.08%, while Vanguard Total Bond Market Index Fund Admiral Shares (VBTLX) has a volatility of 1.17%. This indicates that SSAFX experiences smaller price fluctuations and is considered to be less risky than VBTLX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	SSAFX	VBTLX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.08%	1.17%	-0.09%
Volatility (6M) Calculated over the trailing 6-month period	2.74%	2.88%	-0.14%
Volatility (1Y) Calculated over the trailing 1-year period	3.69%	3.92%	-0.23%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	5.95%	6.01%	-0.06%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	277.57%	4.99%	+272.58%

SSAFX vs. VBTLX - Expense Ratio Comparison

SSAFX has a 0.02% expense ratio, which is lower than VBTLX's 0.04% 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

SSAFX vs. VBTLX - Dividend Comparison

SSAFX's dividend yield for the trailing twelve months is around 4.17%, more than VBTLX's 3.99% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
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%
VBTLX Vanguard Total Bond Market Index Fund Admiral Shares	3.99%	3.87%	3.69%	3.10%	2.59%	1.96%	2.39%	2.74%	2.57%	2.56%	2.53%	2.82%

Frequently Asked Questions

Can I hold both SSAFX and VBTLX in my portfolio?

With a correlation of 0.92, SSAFX and VBTLX 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, SSAFX or VBTLX?

VBTLX has higher volatility (1.17%) compared to SSAFX (1.08%). In terms of maximum drawdown, SSAFX dropped -18.74% vs VBTLX's -18.81%.

Which has better risk-adjusted returns?

SSAFX currently has the higher Sharpe Ratio (1.21 vs 1.12), 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.