LFAI vs. SPTB

Last updated Jun 4, 2026

LFAI (LifeX 2050 Longevity Income ETF) and SPTB (State Street SPDR Portfolio Treasury ETF) are both Government Bonds funds. LFAI is actively managed, while SPTB is passively managed. Over the past year, LFAI returned 4.26% vs 3.87% for SPTB. With a 0.97 correlation, they move nearly in lockstep. LFAI charges 0.25%/yr vs 0.03%/yr for SPTB.

Performance

LFAI vs. SPTB - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in LifeX 2050 Longevity Income ETF (LFAI) and State Street SPDR Portfolio Treasury ETF (SPTB). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, LFAI achieves a -0.43% return, which is significantly lower than SPTB's -0.07% return.

LFAI

• 1D: -0.31%
• 1M: 0.37%
• YTD: -0.43%
• 6M: -1.22%
• 1Y: 4.26%
• 3Y*: —
• 5Y*: —
• 10Y*: —

SPTB

• 1D: -0.22%
• 1M: 0.08%
• YTD: -0.07%
• 6M: -0.37%
• 1Y: 3.87%
• 3Y*: —
• 5Y*: —
• 10Y*: —

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

LFAI vs. SPTB - Yearly Performance Comparison

	2026 (YTD)	2025	2024
LFAI LifeX 2050 Longevity Income ETF	-0.43%	6.06%	-7.12%
SPTB State Street SPDR Portfolio Treasury ETF	-0.07%	6.14%	-3.99%

Correlation

The correlation between LFAI and SPTB is 0.97 - these two move nearly in lockstep. At this level, holding both provides almost no diversification benefit. If you already own one, adding the other does little to reduce portfolio risk.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.97
Correlation (All Time) Calculated using the full available price history since Sep 17, 2024	0.97

The correlation between LFAI and SPTB has been stable across timeframes, ranging from 0.97 to 0.97 - a consistent structural relationship.

Return for Risk

LFAI vs. SPTB — Risk / Return Rank

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

LFAI

LFAI Risk / Return Rank: 20
LFAI Sharpe Ratio Rank: 21
LFAI Sortino Ratio Rank: 20
LFAI Omega Ratio Rank: 19
LFAI Calmar Ratio Rank: 20
LFAI Martin Ratio Rank: 20

SPTB

SPTB Risk / Return Rank: 29
SPTB Sharpe Ratio Rank: 29
SPTB Sortino Ratio Rank: 30
SPTB Omega Ratio Rank: 28
SPTB Calmar Ratio Rank: 28
SPTB Martin Ratio Rank: 28

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.

LFAI vs. SPTB - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for LifeX 2050 Longevity Income ETF (LFAI) and State Street SPDR Portfolio Treasury ETF (SPTB). 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.

	LFAI	SPTB	Difference
Sharpe ratio Return per unit of total volatility	0.68	1.07	-0.39
Sortino ratio Return per unit of downside risk	1.02	1.62	-0.59
Omega ratio Gain probability vs. loss probability	1.12	1.19	-0.07
Calmar ratio Return relative to maximum drawdown	0.81	1.34	-0.53
Martin ratio Return relative to average drawdown	2.28	3.98	-1.69
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

LFAI vs. SPTB - Sharpe Ratio Comparison

The current LFAI Sharpe Ratio is 0.68, which is lower than the SPTB Sharpe Ratio of 1.07. The chart below compares the historical Sharpe Ratios of LFAI and SPTB, 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

	LFAI	SPTB	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	0.68	1.07	-0.39
Sharpe Ratio (All Time) Calculated using the full available price history	-0.16	0.92	-1.08

Drawdowns

LFAI vs. SPTB - Drawdown Comparison

The maximum LFAI drawdown since its inception was -8.64%, which is greater than SPTB's maximum drawdown of -4.96%. Use the drawdown chart below to compare losses from any high point for LFAI and SPTB.

Drawdown Indicators

	LFAI	SPTB	Difference
Max Drawdown Largest peak-to-trough decline	-8.64%	-4.96%	-3.68%
Max Drawdown (1Y) Largest decline over 1 year	-5.30%	-2.90%	-2.40%
Current Drawdown Current decline from peak	-3.38%	-1.94%	-1.44%
Average Drawdown Average peak-to-trough decline	-3.52%	-1.32%	-2.20%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.87%	0.98%	+0.89%

Volatility

LFAI vs. SPTB - Volatility Comparison

LifeX 2050 Longevity Income ETF (LFAI) has a higher volatility of 2.03% compared to State Street SPDR Portfolio Treasury ETF (SPTB) at 1.11%. This indicates that LFAI's price experiences larger fluctuations and is considered to be riskier than SPTB based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	LFAI	SPTB	Difference
Volatility (1M) Calculated over the trailing 1-month period	2.03%	1.11%	+0.92%
Volatility (6M) Calculated over the trailing 6-month period	4.42%	2.47%	+1.95%
Volatility (1Y) Calculated over the trailing 1-year period	6.30%	3.64%	+2.66%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	7.16%	4.42%	+2.74%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	7.16%	4.42%	+2.74%

LFAI vs. SPTB - Expense Ratio Comparison

LFAI has a 0.25% expense ratio, which is higher than SPTB's 0.03% 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

LFAI vs. SPTB - Dividend Comparison

LFAI's dividend yield for the trailing twelve months is around 13.55%, more than SPTB's 4.20% yield.

Position	TTM	2025	2024
LFAI LifeX 2050 Longevity Income ETF	13.55%	16.48%	1.91%
SPTB State Street SPDR Portfolio Treasury ETF	4.20%	4.23%	2.76%

Frequently Asked Questions

Can I hold both LFAI and SPTB in my portfolio?

With a correlation of 0.97, LFAI and SPTB 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, LFAI or SPTB?

LFAI has higher volatility (2.03%) compared to SPTB (1.11%). In terms of maximum drawdown, LFAI dropped -8.64% vs SPTB's -4.96%.

Which ETF is better, LFAI or SPTB?

On 1-year performance, LFAI leads with 4.26% vs 3.87% for SPTB. On fees, SPTB is cheaper at 0.03% per year. On volatility, SPTB has been the lower-risk option at 1.11%. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF has performed better, LFAI or SPTB?

Over the 1-year period, LFAI has performed better with a 4.26% return vs 3.87%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

Which ETF is cheaper, LFAI or SPTB?

SPTB is cheaper with a 0.03% expense ratio, compared with 0.25% for LFAI.

Which ETF pays a higher dividend yield, LFAI or SPTB?

LFAI has the higher dividend yield at 13.55%, compared with 4.20% for SPTB.

What is the main difference between LFAI and SPTB?

They also come from different issuers: Stone Ridge and State Street. Their fees differ too: 0.25% for LFAI and 0.03% for SPTB.

Which has better risk-adjusted returns?

SPTB currently has the higher Sharpe Ratio (1.07 vs 0.68), 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.