ZROZ vs. TFLO

Last updated Apr 1, 2026

Compare and contrast key facts about PIMCO 25+ Year Zero Coupon US Treasury Index Fund (ZROZ) and iShares Treasury Floating Rate Bond ETF (TFLO).

ZROZ and TFLO are both exchange-traded funds (ETFs), meaning they are traded on stock exchanges and can be bought and sold throughout the day. ZROZ is a passively managed fund by PIMCO that tracks the performance of the BofA Merrill Lynch Long Treasury Principal STRIPS Index. It was launched on Oct 30, 2009. TFLO is a passively managed fund by iShares that tracks the performance of the Barclays U.S. Treasury Floating Rate Index. It was launched on Feb 3, 2014. Both ZROZ and TFLO are passive ETFs, meaning that they are not actively managed but aim to replicate the performance of the underlying index as closely as possible.

Performance

ZROZ vs. TFLO - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in PIMCO 25+ Year Zero Coupon US Treasury Index Fund (ZROZ) and iShares Treasury Floating Rate Bond ETF (TFLO). The values are adjusted to include any dividend payments, if applicable.

ZROZ vs. TFLO - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
ZROZ PIMCO 25+ Year Zero Coupon US Treasury Index Fund	-0.37%	-1.84%	-16.18%	1.19%	-41.28%	-5.22%	24.57%	21.22%	-5.43%	14.77%
TFLO iShares Treasury Floating Rate Bond ETF	0.92%	4.22%	5.34%	5.12%	1.99%	-0.02%	0.43%	2.04%	1.76%	1.01%

Returns By Period

In the year-to-date period, ZROZ achieves a -0.37% return, which is significantly lower than TFLO's 0.92% return. Over the past 10 years, ZROZ has underperformed TFLO with an annualized return of -3.82%, while TFLO has yielded a comparatively higher 2.27% annualized return.

ZROZ

• 1D: -0.61%
• 1M: -6.35%
• YTD: -0.37%
• 6M: -3.49%
• 1Y: -6.32%
• 3Y*: -8.90%
• 5Y*: -11.00%
• 10Y*: -3.82%

TFLO

• 1D: 0.00%
• 1M: 0.30%
• YTD: 0.92%
• 6M: 1.98%
• 1Y: 4.08%
• 3Y*: 4.84%
• 5Y*: 3.49%
• 10Y*: 2.27%

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

ZROZ vs. TFLO - Expense Ratio Comparison

Both ZROZ and TFLO have an expense ratio of 0.15%, making them cost-effective options compared to the broader market, where average expense ratios typically range from 0.3% to 0.9%.

ZROZ

PIMCO 25+ Year Zero Coupon US Treasury Index Fund

TFLO

iShares Treasury Floating Rate Bond ETF

Return for Risk

ZROZ vs. TFLO — Risk / Return Rank

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

ZROZ

ZROZ Risk / Return Rank: 7
ZROZ Sharpe Ratio Rank: 6
ZROZ Sortino Ratio Rank: 6
ZROZ Omega Ratio Rank: 6
ZROZ Calmar Ratio Rank: 7
ZROZ Martin Ratio Rank: 8

TFLO

TFLO Risk / Return Rank: 100
TFLO Sharpe Ratio Rank: 100
TFLO Sortino Ratio Rank: 100
TFLO Omega Ratio Rank: 100
TFLO Calmar Ratio Rank: 100
TFLO Martin Ratio Rank: 100

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.

ZROZ vs. TFLO - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for PIMCO 25+ Year Zero Coupon US Treasury Index Fund (ZROZ) and iShares Treasury Floating Rate Bond ETF (TFLO). 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.

	ZROZ	TFLO	Difference
Sharpe ratio Return per unit of total volatility	-0.33	13.83	-14.16
Sortino ratio Return per unit of downside risk	-0.34	45.28	-45.61
Omega ratio Gain probability vs. loss probability	0.96	11.01	-10.05
Calmar ratio Return relative to maximum drawdown	-0.30	207.06	-207.36
Martin ratio Return relative to average drawdown	-0.53	735.43	-735.96
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

ZROZ vs. TFLO - Sharpe Ratio Comparison

The current ZROZ Sharpe Ratio is -0.33, which is lower than the TFLO Sharpe Ratio of 13.83. The chart below compares the historical Sharpe Ratios of ZROZ and TFLO, offering insights into how both investments have performed under varying market conditions. These values are calculated using daily returns over the previous 12 months.

Sharpe Ratios by Period

	ZROZ	TFLO	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	-0.33	13.83	-14.16
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	-0.46	9.83	-10.29
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	-0.17	4.54	-4.71
Sharpe Ratio (All Time) Calculated using the full available price history	0.09	0.96	-0.87

Correlation

The correlation between ZROZ and TFLO is -0.02. This indicates that the assets' prices tend to move in opposite directions. Negative correlation can be particularly beneficial for diversification and risk management, as one asset may offset the losses of the other during market fluctuations.

Dividends

ZROZ vs. TFLO - Dividend Comparison

ZROZ's dividend yield for the trailing twelve months is around 4.98%, more than TFLO's 4.05% yield.

	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
ZROZ PIMCO 25+ Year Zero Coupon US Treasury Index Fund	4.98%	4.96%	4.58%	3.52%	2.76%	1.60%	1.68%	2.22%	2.06%	2.53%	3.00%	2.98%
TFLO iShares Treasury Floating Rate Bond ETF	4.05%	4.16%	5.21%	4.88%	1.68%	0.00%	0.36%	2.08%	1.65%	0.86%	0.31%	0.15%

Drawdowns

ZROZ vs. TFLO - Drawdown Comparison

The maximum ZROZ drawdown since its inception was -62.93%, which is greater than TFLO's maximum drawdown of -5.01%. Use the drawdown chart below to compare losses from any high point for ZROZ and TFLO.

Drawdown Indicators

	ZROZ	TFLO	Difference
Max Drawdown Largest peak-to-trough decline	-62.93%	-5.01%	-57.92%
Max Drawdown (1Y) Largest decline over 1 year	-15.63%	-0.02%	-15.61%
Max Drawdown (5Y) Largest decline over 5 years	-57.98%	-0.13%	-57.85%
Max Drawdown (10Y) Largest decline over 10 years	-62.93%	-0.50%	-62.43%
Current Drawdown Current decline from peak	-59.65%	0.00%	-59.65%
Average Drawdown Average peak-to-trough decline	-23.66%	-0.10%	-23.56%
Ulcer Index Depth and duration of drawdowns from previous peaks	8.99%	0.01%	+8.98%

Volatility

ZROZ vs. TFLO - Volatility Comparison

PIMCO 25+ Year Zero Coupon US Treasury Index Fund (ZROZ) has a higher volatility of 5.79% compared to iShares Treasury Floating Rate Bond ETF (TFLO) at 0.07%. This indicates that ZROZ's price experiences larger fluctuations and is considered to be riskier than TFLO based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	ZROZ	TFLO	Difference
Volatility (1M) Calculated over the trailing 1-month period	5.79%	0.07%	+5.72%
Volatility (6M) Calculated over the trailing 6-month period	10.85%	0.21%	+10.64%
Volatility (1Y) Calculated over the trailing 1-year period	19.16%	0.30%	+18.86%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	23.93%	0.36%	+23.57%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	22.09%	0.50%	+21.59%