SPTS vs. SSAFX

Last updated Jun 4, 2026

SPTS (SPDR Portfolio Short Term Treasury ETF) and SSAFX (State Street Aggregate Bond Index Portfolio) are both funds - SPTS is a Government Bonds fund tracking the Bloomberg U.S. Treasury 1-3 Year Index, while SSAFX is a Intermediate Core Bond fund managed by State Street. Over the past 10 years, SPTS returned 1.67%/yr vs 27.83%/yr for SSAFX. A 0.68 correlation means they provide meaningful diversification when combined. SPTS charges 0.03%/yr vs 0.02%/yr for SSAFX.

Performance

SPTS vs. SSAFX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in SPDR Portfolio Short Term Treasury ETF (SPTS) 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, SPTS achieves a 0.45% return, which is significantly higher than SSAFX's 0.42% return. Over the past 10 years, SPTS has underperformed SSAFX with an annualized return of 1.67%, while SSAFX has yielded a comparatively higher 27.83% annualized return.

SPTS

• 1D: -0.07%
• 1M: 0.05%
• YTD: 0.45%
• 6M: 0.77%
• 1Y: 3.45%
• 3Y*: 4.18%
• 5Y*: 1.81%
• 10Y*: 1.67%

SSAFX

• 1D: 0.05%
• 1M: 0.49%
• YTD: 0.42%
• 6M: 0.33%
• 1Y: 5.39%
• 3Y*: 3.90%
• 5Y*: 0.09%
• 10Y*: 27.83%

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

SPTS vs. SSAFX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
SPTS SPDR Portfolio Short Term Treasury ETF	0.45%	5.05%	4.20%	4.27%	-3.86%	-0.72%	3.23%	3.56%	1.08%	0.59%
SSAFX State Street Aggregate Bond Index Portfolio	0.42%	6.81%	1.34%	5.61%	-13.30%	-1.72%	978.57%	8.69%	-0.12%	3.38%

Correlation

The correlation between SPTS and SSAFX is 0.81, 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	0.81
Correlation (3Y) Calculated over the trailing 3-year period	0.76
Correlation (5Y) Calculated over the trailing 5-year period	0.76
Correlation (10Y) Calculated over the trailing 10-year period	0.69
Correlation (All Time) Calculated using the full available price history since Sep 23, 2014	0.68

The correlation between SPTS and SSAFX shifts across timeframes, from 0.68 (all time) to 0.81 (1 year), reflecting how their relationship changes across market environments.

Return for Risk

SPTS vs. SSAFX — Risk / Return Rank

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

SPTS

SPTS Risk / Return Rank: 84
SPTS Sharpe Ratio Rank: 79
SPTS Sortino Ratio Rank: 91
SPTS Omega Ratio Rank: 87
SPTS Calmar Ratio Rank: 79
SPTS Martin Ratio Rank: 82

SSAFX

SSAFX Risk / Return Rank: 26
SSAFX Sharpe Ratio Rank: 26
SSAFX Sortino Ratio Rank: 27
SSAFX Omega Ratio Rank: 24
SSAFX Calmar Ratio Rank: 27
SSAFX Martin Ratio Rank: 24

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.

SPTS vs. SSAFX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for SPDR Portfolio Short Term Treasury ETF (SPTS) 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.

	SPTS	SSAFX	Difference
Sharpe ratio: Return per unit of total volatility	2.63	1.45	+1.19
Sortino ratio: Return per unit of downside risk	4.47	2.17	+2.30
Omega ratio: Gain probability vs. loss probability	1.55	1.26	+0.29
Calmar ratio: Return relative to maximum drawdown	4.13	1.96	+2.16
Martin ratio: Return relative to average drawdown	16.52	6.00	+10.52
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

SPTS vs. SSAFX - Sharpe Ratio Comparison

The current SPTS Sharpe Ratio is 2.63, which is higher than the SSAFX Sharpe Ratio of 1.45. The chart below compares the historical Sharpe Ratios of SPTS 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

	SPTS	SSAFX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.63	1.45	+1.19
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.92	0.01	+0.90
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.98	0.10	+0.88
Sharpe Ratio (All Time) Calculated using the full available price history	0.49	0.09	+0.40

Drawdowns

SPTS vs. SSAFX - Drawdown Comparison

The maximum SPTS drawdown since its inception was -5.83%, smaller than the maximum SSAFX drawdown of -18.74%. Use the drawdown chart below to compare losses from any high point for SPTS and SSAFX.

Drawdown Indicators

	SPTS	SSAFX	Difference
Max Drawdown Largest peak-to-trough decline	-5.83%	-18.74%	+12.91%
Max Drawdown (1Y) Largest decline over 1 year	-0.84%	-2.74%	+1.90%
Max Drawdown (3Y) Largest decline over 3 years	-0.96%	-6.09%	+5.13%
Max Drawdown (5Y) Largest decline over 5 years	-5.71%	-18.10%	+12.39%
Max Drawdown (10Y) Largest decline over 10 years	-5.71%	-18.74%	+13.03%
Current Drawdown Current decline from peak	-0.28%	-2.62%	+2.34%
Average Drawdown Average peak-to-trough decline	-1.72%	-4.41%	+2.69%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.21%	0.90%	-0.69%

Volatility

SPTS vs. SSAFX - Volatility Comparison

The current volatility for SPDR Portfolio Short Term Treasury ETF (SPTS) is 0.34%, while State Street Aggregate Bond Index Portfolio (SSAFX) has a volatility of 1.29%. This indicates that SPTS experiences smaller price fluctuations and is considered to be less risky than SSAFX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	SPTS	SSAFX	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.34%	1.29%	-0.95%
Volatility (6M) Calculated over the trailing 6-month period	0.86%	2.65%	-1.79%
Volatility (1Y) Calculated over the trailing 1-year period	1.32%	3.74%	-2.42%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	1.98%	5.95%	-3.97%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	1.72%	277.51%	-275.79%

SPTS vs. SSAFX - Expense Ratio Comparison

SPTS has a 0.03% expense ratio, which is higher than SSAFX's 0.02% expense ratio. However, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.

Dividends

SPTS vs. SSAFX - Dividend Comparison

SPTS's dividend yield for the trailing twelve months is around 3.91%, less than SSAFX's 4.16% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
SPTS SPDR Portfolio Short Term Treasury ETF	3.91%	3.99%	4.25%	3.61%	1.27%	0.19%	0.70%	2.21%	2.04%	1.20%	0.95%	0.83%
SSAFX State Street Aggregate Bond Index Portfolio	4.16%	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 SPTS and SSAFX in my portfolio?

SPTS and SSAFX have a correlation of 0.81, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, SPTS or SSAFX?

SSAFX has higher volatility (1.29%) compared to SPTS (0.34%). In terms of maximum drawdown, SPTS dropped -5.83% vs SSAFX's -18.74%.

Which has better risk-adjusted returns?

SPTS currently has the higher Sharpe Ratio (2.63 vs 1.45), 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.