TBIIX vs. FXNAX

Last updated Jun 24, 2026

TBIIX (TIAA-CREF Bond Index Fund) and FXNAX (Fidelity U.S. Bond Index Fund) are both mutual funds - TBIIX is a Intermediate Core Bond fund managed by TIAA Investments, while FXNAX is a Total Bond Market fund tracking the Bloomberg U.S. Aggregate Bond Index. Over the past 10 years, TBIIX returned 1.33%/yr vs 1.44%/yr for FXNAX. With a 0.96 correlation, they move nearly in lockstep. TBIIX charges 0.07%/yr vs 0.03%/yr for FXNAX.

Performance

TBIIX vs. FXNAX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in TIAA-CREF Bond Index Fund (TBIIX) and Fidelity U.S. Bond Index Fund (FXNAX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, TBIIX achieves a 0.10% return, which is significantly lower than FXNAX's 0.11% return. Over the past 10 years, TBIIX has underperformed FXNAX with an annualized return of 1.33%, while FXNAX has yielded a comparatively higher 1.44% annualized return.

TBIIX

• 1D: -0.31%
• 1M: 0.55%
• YTD: 0.10%
• 6M: 0.42%
• 1Y: 4.17%
• 3Y*: 3.70%
• 5Y*: -0.27%
• 10Y*: 1.33%

FXNAX

• 1D: -0.29%
• 1M: 0.61%
• YTD: 0.11%
• 6M: 0.43%
• 1Y: 4.25%
• 3Y*: 3.88%
• 5Y*: -0.05%
• 10Y*: 1.44%

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

TBIIX vs. FXNAX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
TBIIX TIAA-CREF Bond Index Fund	0.10%	7.12%	1.13%	5.13%	-13.61%	-1.81%	7.69%	8.58%	-0.25%	3.43%
FXNAX Fidelity U.S. Bond Index Fund	0.11%	7.14%	1.35%	5.82%	-13.55%	-2.10%	7.63%	8.50%	0.04%	3.50%

Correlation

The correlation between TBIIX and FXNAX is 0.95 - 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	0.95
Correlation (3Y) Calculated over the trailing 3-year period	0.97
Correlation (5Y) Calculated over the trailing 5-year period	0.98
Correlation (10Y) Calculated over the trailing 10-year period	0.97
Correlation (All Time) Calculated using the full available price history since May 4, 2011	0.96

The correlation between TBIIX and FXNAX has been stable across timeframes, ranging from 0.95 to 0.98 - a consistent structural relationship.

Return for Risk

TBIIX vs. FXNAX — Risk / Return Rank

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

TBIIX

TBIIX Risk / Return Rank: 17
TBIIX Sharpe Ratio Rank: 17
TBIIX Sortino Ratio Rank: 18
TBIIX Omega Ratio Rank: 15
TBIIX Calmar Ratio Rank: 19
TBIIX Martin Ratio Rank: 17

FXNAX

FXNAX Risk / Return Rank: 18
FXNAX Sharpe Ratio Rank: 18
FXNAX Sortino Ratio Rank: 20
FXNAX Omega Ratio Rank: 17
FXNAX Calmar Ratio Rank: 20
FXNAX Martin Ratio Rank: 18

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.

TBIIX vs. FXNAX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for TIAA-CREF Bond Index Fund (TBIIX) and Fidelity U.S. Bond Index Fund (FXNAX). 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.

	TBIIX	FXNAX	Difference
Sharpe ratio: Return per unit of total volatility	1.10	1.14	-0.05
Sortino ratio: Return per unit of downside risk	1.64	1.73	-0.09
Omega ratio: Gain probability vs. loss probability	1.19	1.20	-0.01
Calmar ratio: Return relative to maximum drawdown	1.48	1.52	-0.04
Martin ratio: Return relative to average drawdown	4.21	4.36	-0.15

TBIIX vs. FXNAX - Sharpe Ratio Comparison

The current TBIIX Sharpe Ratio is 1.10, which is comparable to the FXNAX Sharpe Ratio of 1.14. The chart below compares the historical Sharpe Ratios of TBIIX and FXNAX, 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

TBIIX vs. FXNAX - Drawdown Comparison

The maximum TBIIX drawdown since its inception was -19.33%, roughly equal to the maximum FXNAX drawdown of -19.51%. Use the drawdown chart below to compare losses from any high point for TBIIX and FXNAX.

Drawdown Indicators

	TBIIX	FXNAX	Difference
Max Drawdown Largest peak-to-trough decline	-19.33%	-19.51%	+0.18%
Max Drawdown (1Y) Largest decline over 1 year	-2.99%	-2.94%	-0.05%
Max Drawdown (3Y) Largest decline over 3 years	-6.17%	-6.16%	-0.01%
Max Drawdown (5Y) Largest decline over 5 years	-18.68%	-18.54%	-0.14%
Max Drawdown (10Y) Largest decline over 10 years	-19.33%	-19.51%	+0.18%
Current Drawdown Current decline from peak	-3.79%	-3.17%	-0.62%
Average Drawdown Average peak-to-trough decline	-3.68%	-3.86%	+0.18%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.04%	1.02%	+0.02%

Volatility

TBIIX vs. FXNAX - Volatility Comparison

TIAA-CREF Bond Index Fund (TBIIX) and Fidelity U.S. Bond Index Fund (FXNAX) have volatilities of 1.19% and 1.16%, respectively, indicating that both stocks experience similar levels of price fluctuations. This suggests that the risk associated with both stocks, as measured by volatility, is nearly the same. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	TBIIX	FXNAX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.19%	1.16%	+0.03%
Volatility (6M) Calculated over the trailing 6-month period	2.96%	2.90%	+0.06%
Volatility (1Y) Calculated over the trailing 1-year period	4.03%	3.92%	+0.11%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	6.08%	6.08%	0.00%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	5.02%	5.01%	+0.01%

TBIIX vs. FXNAX - Expense Ratio Comparison

TBIIX has a 0.07% expense ratio, which is higher than FXNAX'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

TBIIX vs. FXNAX - Dividend Comparison

TBIIX's dividend yield for the trailing twelve months is around 3.91%, more than FXNAX's 3.72% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FXNAX Fidelity U.S. Bond Index Fund	3.72%	3.58%	3.40%	3.15%	1.81%	1.74%	2.92%	2.68%	2.74%	2.57%	2.76%	2.52%
TBIIX TIAA-CREF Bond Index Fund	3.91%	3.73%	3.14%	2.44%	2.11%	2.07%	3.17%	2.82%	2.46%	2.44%	2.31%	2.61%

Frequently Asked Questions

Can I hold both TBIIX and FXNAX in my portfolio?

With a correlation of 0.95, TBIIX and FXNAX 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, TBIIX or FXNAX?

TBIIX has higher volatility (1.19%) compared to FXNAX (1.16%). In terms of maximum drawdown, TBIIX dropped -19.33% vs FXNAX's -19.51%.

Which has better risk-adjusted returns?

FXNAX currently has the higher Sharpe Ratio (1.14 vs 1.10), 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.