TSBIX vs. FIBUX

Last updated Jun 4, 2026

TSBIX (TIAA-CREF Core Impact Bond Fund Institutional Class) and FIBUX (Fidelity Flex U.S. Bond Index Fund) are both Total Bond Market funds. Over the past 5 years, TSBIX returned 0.67%/yr vs 0.09%/yr for FIBUX. Their correlation of 0.95 suggests significant overlap in exposure. TSBIX charges 0.35%/yr vs 0.00%/yr for FIBUX.

Performance

TSBIX vs. FIBUX - Performance Comparison

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

Returns By Period

In the year-to-date period, TSBIX achieves a 0.68% return, which is significantly higher than FIBUX's 0.46% return.

TSBIX

• 1D: 0.00%
• 1M: 0.47%
• YTD: 0.68%
• 6M: 0.98%
• 1Y: 6.46%
• 3Y*: 5.32%
• 5Y*: 0.67%
• 10Y*: 2.12%

FIBUX

• 1D: 0.00%
• 1M: 0.46%
• YTD: 0.46%
• 6M: 0.33%
• 1Y: 5.40%
• 3Y*: 4.04%
• 5Y*: 0.09%
• 10Y*: —

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

TSBIX vs. FIBUX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
TSBIX TIAA-CREF Core Impact Bond Fund Institutional Class	0.68%	8.69%	3.32%	6.05%	-14.43%	-1.03%	7.43%	8.94%	0.08%	4.40%
FIBUX Fidelity Flex U.S. Bond Index Fund	0.46%	7.20%	1.31%	5.46%	-13.41%	-2.16%	7.08%	8.58%	0.12%	3.81%

Correlation

The correlation between TSBIX and FIBUX is 0.94, 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	0.94
Correlation (3Y) Calculated over the trailing 3-year period	0.96
Correlation (5Y) Calculated over the trailing 5-year period	0.97
Correlation (All Time) Calculated using the full available price history since Mar 10, 2017	0.95

The correlation between TSBIX and FIBUX has been stable across timeframes, ranging from 0.94 to 0.97 - a consistent structural relationship.

Return for Risk

TSBIX vs. FIBUX — Risk / Return Rank

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

TSBIX

TSBIX Risk / Return Rank: 34
TSBIX Sharpe Ratio Rank: 34
TSBIX Sortino Ratio Rank: 38
TSBIX Omega Ratio Rank: 33
TSBIX Calmar Ratio Rank: 36
TSBIX Martin Ratio Rank: 29

FIBUX

FIBUX Risk / Return Rank: 23
FIBUX Sharpe Ratio Rank: 23
FIBUX Sortino Ratio Rank: 24
FIBUX Omega Ratio Rank: 22
FIBUX Calmar Ratio Rank: 24
FIBUX Martin Ratio Rank: 21

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.

TSBIX vs. FIBUX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for TIAA-CREF Core Impact Bond Fund Institutional Class (TSBIX) and Fidelity Flex U.S. Bond Index Fund (FIBUX). 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.

	TSBIX	FIBUX	Difference
Sharpe ratio: Return per unit of total volatility	1.68	1.36	+0.32
Sortino ratio: Return per unit of downside risk	2.57	2.03	+0.54
Omega ratio: Gain probability vs. loss probability	1.30	1.24	+0.06
Calmar ratio: Return relative to maximum drawdown	2.27	1.83	+0.44
Martin ratio: Return relative to average drawdown	6.80	5.45	+1.35
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

TSBIX vs. FIBUX - Sharpe Ratio Comparison

The current TSBIX Sharpe Ratio is 1.68, which is comparable to the FIBUX Sharpe Ratio of 1.36. The chart below compares the historical Sharpe Ratios of TSBIX and FIBUX, 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

	TSBIX	FIBUX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.68	1.36	+0.32
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.12	0.02	+0.10
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.44	—	—
Sharpe Ratio (All Time) Calculated using the full available price history	0.56	0.35	+0.21

Drawdowns

TSBIX vs. FIBUX - Drawdown Comparison

The maximum TSBIX drawdown since its inception was -19.21%, roughly equal to the maximum FIBUX drawdown of -19.76%. Use the drawdown chart below to compare losses from any high point for TSBIX and FIBUX.

Drawdown Indicators

	TSBIX	FIBUX	Difference
Max Drawdown Largest peak-to-trough decline	-19.21%	-19.76%	+0.55%
Max Drawdown (1Y) Largest decline over 1 year	-2.87%	-2.97%	+0.10%
Max Drawdown (3Y) Largest decline over 3 years	-6.11%	-6.09%	-0.02%
Max Drawdown (5Y) Largest decline over 5 years	-19.21%	-18.40%	-0.81%
Max Drawdown (10Y) Largest decline over 10 years	-19.21%	—	—
Current Drawdown Current decline from peak	-1.32%	-3.43%	+2.11%
Average Drawdown Average peak-to-trough decline	-3.56%	-5.79%	+2.23%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.95%	1.00%	-0.05%

Volatility

TSBIX vs. FIBUX - Volatility Comparison

TIAA-CREF Core Impact Bond Fund Institutional Class (TSBIX) and Fidelity Flex U.S. Bond Index Fund (FIBUX) have volatilities of 1.34% and 1.38%, 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

	TSBIX	FIBUX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.34%	1.38%	-0.04%
Volatility (6M) Calculated over the trailing 6-month period	2.81%	2.86%	-0.05%
Volatility (1Y) Calculated over the trailing 1-year period	3.89%	4.02%	-0.13%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	5.83%	6.04%	-0.21%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	4.85%	5.11%	-0.26%

TSBIX vs. FIBUX - Expense Ratio Comparison

TSBIX has a 0.35% expense ratio, which is higher than FIBUX's 0.00% expense ratio.

Dividends

TSBIX vs. FIBUX - Dividend Comparison

TSBIX's dividend yield for the trailing twelve months is around 4.72%, more than FIBUX's 4.08% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FIBUX Fidelity Flex U.S. Bond Index Fund	4.08%	3.95%	3.65%	2.93%	1.62%	1.18%	2.32%	2.96%	2.70%	2.45%	0.00%	0.00%
TSBIX TIAA-CREF Core Impact Bond Fund Institutional Class	4.72%	5.38%	5.10%	3.77%	2.31%	1.69%	4.56%	3.68%	2.63%	2.45%	3.19%	2.89%

Frequently Asked Questions

Can I hold both TSBIX and FIBUX in my portfolio?

With a correlation of 0.94, TSBIX and FIBUX 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, TSBIX or FIBUX?

FIBUX has higher volatility (1.38%) compared to TSBIX (1.34%). In terms of maximum drawdown, TSBIX dropped -19.21% vs FIBUX's -19.76%.

Which has better risk-adjusted returns?

TSBIX currently has the higher Sharpe Ratio (1.68 vs 1.36), 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.