FNBGX vs. TIBDX

Last updated Jun 5, 2026

FNBGX (Fidelity Long-Term Treasury Bond Index Fund) and TIBDX (TIAA-CREF Core Bond Fund) are both mutual funds - FNBGX is a Government Bonds fund managed by Fidelity, while TIBDX is a Intermediate Core-Plus Bond fund managed by TIAA Investments. Over the past 5 years, FNBGX returned -5.43%/yr vs 0.15%/yr for TIBDX. Their correlation of 0.87 suggests significant overlap in exposure. FNBGX charges 0.03%/yr vs 0.29%/yr for TIBDX.

Performance

FNBGX vs. TIBDX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Fidelity Long-Term Treasury Bond Index Fund (FNBGX) and TIAA-CREF Core Bond Fund (TIBDX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, FNBGX achieves a -0.41% return, which is significantly lower than TIBDX's 0.45% return.

FNBGX

• 1D: -0.44%
• 1M: 0.24%
• YTD: -0.41%
• 6M: -1.25%
• 1Y: 3.67%
• 3Y*: -0.69%
• 5Y*: -5.43%
• 10Y*: —

TIBDX

• 1D: -0.22%
• 1M: 0.16%
• YTD: 0.45%
• 6M: 0.61%
• 1Y: 5.22%
• 3Y*: 4.26%
• 5Y*: 0.15%
• 10Y*: 1.97%

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

FNBGX vs. TIBDX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
FNBGX Fidelity Long-Term Treasury Bond Index Fund	-0.41%	5.30%	-6.18%	3.20%	-29.89%	-5.17%	17.58%	14.24%	-1.62%	1.86%
TIBDX TIAA-CREF Core Bond Fund	0.45%	7.38%	1.95%	5.63%	-13.68%	-0.95%	8.10%	9.57%	-0.64%	0.40%

Correlation

The correlation between FNBGX and TIBDX is 0.89, 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	0.89
Correlation (3Y) Calculated over the trailing 3-year period	0.93
Correlation (5Y) Calculated over the trailing 5-year period	0.92
Correlation (All Time) Calculated using the full available price history since Oct 20, 2017	0.87

The correlation between FNBGX and TIBDX has been stable across timeframes, ranging from 0.87 to 0.93 - a consistent structural relationship.

Return for Risk

FNBGX vs. TIBDX — Risk / Return Rank

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

FNBGX

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

TIBDX

TIBDX Risk / Return Rank: 28
TIBDX Sharpe Ratio Rank: 28
TIBDX Sortino Ratio Rank: 29
TIBDX Omega Ratio Rank: 28
TIBDX Calmar Ratio Rank: 28
TIBDX Martin Ratio Rank: 25

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.

FNBGX vs. TIBDX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Fidelity Long-Term Treasury Bond Index Fund (FNBGX) and TIAA-CREF Core Bond Fund (TIBDX). 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.

	FNBGX	TIBDX	Difference
Sharpe ratio: Return per unit of total volatility	0.59	1.50	-0.91
Sortino ratio: Return per unit of downside risk	0.90	2.24	-1.34
Omega ratio: Gain probability vs. loss probability	1.10	1.27	-0.17
Calmar ratio: Return relative to maximum drawdown	0.73	1.96	-1.23
Martin ratio: Return relative to average drawdown	1.92	6.09	-4.17
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

FNBGX vs. TIBDX - Sharpe Ratio Comparison

The current FNBGX Sharpe Ratio is 0.59, which is lower than the TIBDX Sharpe Ratio of 1.50. The chart below compares the historical Sharpe Ratios of FNBGX and TIBDX, 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

	FNBGX	TIBDX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	0.59	1.50	-0.91
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	-0.37	0.03	-0.40
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	—	0.42	—
Sharpe Ratio (All Time) Calculated using the full available price history	-0.08	0.95	-1.03

Drawdowns

FNBGX vs. TIBDX - Drawdown Comparison

The maximum FNBGX drawdown since its inception was -46.86%, which is greater than TIBDX's maximum drawdown of -18.82%. Use the drawdown chart below to compare losses from any high point for FNBGX and TIBDX.

Drawdown Indicators

	FNBGX	TIBDX	Difference
Max Drawdown Largest peak-to-trough decline	-46.86%	-18.82%	-28.04%
Max Drawdown (1Y) Largest decline over 1 year	-7.28%	-2.98%	-4.30%
Max Drawdown (3Y) Largest decline over 3 years	-17.66%	-6.29%	-11.37%
Max Drawdown (5Y) Largest decline over 5 years	-41.54%	-18.82%	-22.72%
Max Drawdown (10Y) Largest decline over 10 years	—	-18.82%	—
Current Drawdown Current decline from peak	-37.51%	-1.43%	-36.08%
Average Drawdown Average peak-to-trough decline	-21.65%	-2.30%	-19.35%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.76%	0.96%	+1.80%

Volatility

FNBGX vs. TIBDX - Volatility Comparison

Fidelity Long-Term Treasury Bond Index Fund (FNBGX) has a higher volatility of 2.71% compared to TIAA-CREF Core Bond Fund (TIBDX) at 1.33%. This indicates that FNBGX's price experiences larger fluctuations and is considered to be riskier than TIBDX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	FNBGX	TIBDX	Difference
Volatility (1M) Calculated over the trailing 1-month period	2.71%	1.33%	+1.38%
Volatility (6M) Calculated over the trailing 6-month period	6.04%	2.88%	+3.16%
Volatility (1Y) Calculated over the trailing 1-year period	8.99%	3.90%	+5.09%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	14.59%	5.63%	+8.96%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	14.20%	4.73%	+9.47%

FNBGX vs. TIBDX - Expense Ratio Comparison

FNBGX has a 0.03% expense ratio, which is lower than TIBDX's 0.29% expense ratio.

Dividends

FNBGX vs. TIBDX - Dividend Comparison

FNBGX's dividend yield for the trailing twelve months is around 4.01%, less than TIBDX's 4.46% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FNBGX Fidelity Long-Term Treasury Bond Index Fund	4.01%	3.88%	3.75%	3.20%	2.26%	2.47%	3.96%	2.63%	2.93%	0.70%	0.00%	0.00%
TIBDX TIAA-CREF Core Bond Fund	4.46%	4.34%	3.60%	3.22%	2.44%	2.39%	4.45%	3.09%	2.88%	2.93%	3.80%	4.68%

Frequently Asked Questions

Can I hold both FNBGX and TIBDX in my portfolio?

FNBGX and TIBDX have a correlation of 0.89, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, FNBGX or TIBDX?

FNBGX has higher volatility (2.71%) compared to TIBDX (1.33%). In terms of maximum drawdown, FNBGX dropped -46.86% vs TIBDX's -18.82%.

Which has better risk-adjusted returns?

TIBDX currently has the higher Sharpe Ratio (1.50 vs 0.59), 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.