MFIOX vs. TIBDX

Last updated Jun 4, 2026

MFIOX (MFS Income Fund) and TIBDX (TIAA-CREF Core Bond Fund) are both Intermediate Core-Plus Bond funds. Over the past 10 years, MFIOX returned 2.75%/yr vs 1.99%/yr for TIBDX. A 0.73 correlation means they provide meaningful diversification when combined. MFIOX charges 0.73%/yr vs 0.29%/yr for TIBDX.

Performance

MFIOX vs. TIBDX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in MFS Income Fund (MFIOX) 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, MFIOX achieves a 0.63% return, which is significantly lower than TIBDX's 0.67% return. Over the past 10 years, MFIOX has outperformed TIBDX with an annualized return of 2.75%, while TIBDX has yielded a comparatively lower 1.99% annualized return.

MFIOX

• 1D: 0.00%
• 1M: 0.58%
• YTD: 0.63%
• 6M: 0.68%
• 1Y: 5.85%
• 3Y*: 5.05%
• 5Y*: 0.75%
• 10Y*: 2.75%

TIBDX

• 1D: 0.00%
• 1M: 0.60%
• YTD: 0.67%
• 6M: 0.72%
• 1Y: 6.03%
• 3Y*: 4.33%
• 5Y*: 0.25%
• 10Y*: 1.99%

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

MFIOX vs. TIBDX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
MFIOX MFS Income Fund	0.63%	7.37%	2.66%	7.46%	-14.14%	-0.28%	9.47%	11.36%	-2.38%	5.73%
TIBDX TIAA-CREF Core Bond Fund	0.67%	7.38%	1.95%	5.63%	-13.68%	-0.95%	8.10%	9.57%	-0.64%	4.48%

Correlation

The correlation between MFIOX and TIBDX is 0.93, 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	0.93
Correlation (3Y) Calculated over the trailing 3-year period	0.95
Correlation (5Y) Calculated over the trailing 5-year period	0.95
Correlation (10Y) Calculated over the trailing 10-year period	0.90
Correlation (All Time) Calculated using the full available price history since Jun 15, 1999	0.73

The correlation between MFIOX and TIBDX shifts across timeframes, from 0.73 (all time) to 0.95 (5 years), reflecting how their relationship changes across market environments.

Return for Risk

MFIOX vs. TIBDX — Risk / Return Rank

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

MFIOX

MFIOX Risk / Return Rank: 31
MFIOX Sharpe Ratio Rank: 31
MFIOX Sortino Ratio Rank: 33
MFIOX Omega Ratio Rank: 33
MFIOX Calmar Ratio Rank: 31
MFIOX Martin Ratio Rank: 28

TIBDX

TIBDX Risk / Return Rank: 30
TIBDX Sharpe Ratio Rank: 30
TIBDX Sortino Ratio Rank: 32
TIBDX Omega Ratio Rank: 30
TIBDX Calmar Ratio Rank: 30
TIBDX Martin Ratio Rank: 26

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.

MFIOX vs. TIBDX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for MFS Income Fund (MFIOX) 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.

	MFIOX	TIBDX	Difference
Sharpe ratio: Return per unit of total volatility	1.59	1.56	+0.03
Sortino ratio: Return per unit of downside risk	2.39	2.34	+0.05
Omega ratio: Gain probability vs. loss probability	1.30	1.29	+0.01
Calmar ratio: Return relative to maximum drawdown	2.09	2.04	+0.05
Martin ratio: Return relative to average drawdown	6.63	6.36	+0.27
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

MFIOX vs. TIBDX - Sharpe Ratio Comparison

The current MFIOX Sharpe Ratio is 1.59, which is comparable to the TIBDX Sharpe Ratio of 1.56. The chart below compares the historical Sharpe Ratios of MFIOX 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

	MFIOX	TIBDX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.59	1.56	+0.03
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.14	0.05	+0.09
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.57	0.42	+0.14
Sharpe Ratio (All Time) Calculated using the full available price history	1.36	0.95	+0.41

Drawdowns

MFIOX vs. TIBDX - Drawdown Comparison

The maximum MFIOX drawdown since its inception was -19.07%, roughly equal to the maximum TIBDX drawdown of -18.82%. Use the drawdown chart below to compare losses from any high point for MFIOX and TIBDX.

Drawdown Indicators

	MFIOX	TIBDX	Difference
Max Drawdown Largest peak-to-trough decline	-19.07%	-18.82%	-0.25%
Max Drawdown (1Y) Largest decline over 1 year	-2.81%	-2.98%	+0.17%
Max Drawdown (3Y) Largest decline over 3 years	-5.88%	-6.29%	+0.41%
Max Drawdown (5Y) Largest decline over 5 years	-19.07%	-18.82%	-0.25%
Max Drawdown (10Y) Largest decline over 10 years	-19.07%	-18.82%	-0.25%
Current Drawdown Current decline from peak	-0.97%	-1.22%	+0.25%
Average Drawdown Average peak-to-trough decline	-2.18%	-2.30%	+0.12%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.88%	0.95%	-0.07%

Volatility

MFIOX vs. TIBDX - Volatility Comparison

The current volatility for MFS Income Fund (MFIOX) is 1.29%, while TIAA-CREF Core Bond Fund (TIBDX) has a volatility of 1.39%. This indicates that MFIOX experiences smaller price fluctuations and is considered to be less risky than TIBDX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	MFIOX	TIBDX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.29%	1.39%	-0.10%
Volatility (6M) Calculated over the trailing 6-month period	2.59%	2.88%	-0.29%
Volatility (1Y) Calculated over the trailing 1-year period	3.69%	3.90%	-0.21%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	5.51%	5.63%	-0.12%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	4.87%	4.73%	+0.14%

MFIOX vs. TIBDX - Expense Ratio Comparison

MFIOX has a 0.73% expense ratio, which is higher than TIBDX's 0.29% expense ratio.

Dividends

MFIOX vs. TIBDX - Dividend Comparison

MFIOX's dividend yield for the trailing twelve months is around 4.70%, more than TIBDX's 4.45% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
MFIOX MFS Income Fund	4.70%	4.70%	5.04%	4.72%	2.24%	3.29%	2.80%	3.04%	3.07%	3.26%	3.61%	4.35%
TIBDX TIAA-CREF Core Bond Fund	4.45%	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 MFIOX and TIBDX in my portfolio?

With a correlation of 0.93, MFIOX and TIBDX 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, MFIOX or TIBDX?

TIBDX has higher volatility (1.39%) compared to MFIOX (1.29%). In terms of maximum drawdown, MFIOX dropped -19.07% vs TIBDX's -18.82%.

Which has better risk-adjusted returns?

MFIOX currently has the higher Sharpe Ratio (1.59 vs 1.56), 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.