BUFBX vs. TWEIX

Last updated Jul 16, 2026

BUFBX (Buffalo Flexible Income Fund) and TWEIX (American Century Equity Income Fund) are both Large Cap Value Equities funds. Over the past 10 years, BUFBX returned 9.30%/yr vs 8.58%/yr for TWEIX. Their correlation of 0.82 suggests significant overlap in exposure. BUFBX charges 1.01%/yr vs 0.94%/yr for TWEIX.

Performance

BUFBX vs. TWEIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Buffalo Flexible Income Fund (BUFBX) and American Century Equity Income Fund (TWEIX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

The year-to-date returns for both investments are quite close, with BUFBX having a 9.91% return and TWEIX slightly higher at 10.31%. Over the past 10 years, BUFBX has outperformed TWEIX with an annualized return of 9.30%, while TWEIX has yielded a comparatively lower 8.58% annualized return.

BUFBX

• 1D: -2.11%
• 1M: -0.46%
• 6M: 7.24%
• YTD: 9.91%
• 1Y: 15.39%
• 3Y*: 12.32%
• 5Y*: 10.70%
• 10Y*: 9.30%

TWEIX

• 1D: -0.54%
• 1M: 1.99%
• 6M: 7.89%
• YTD: 10.31%
• 1Y: 17.14%
• 3Y*: 11.45%
• 5Y*: 7.58%
• 10Y*: 8.58%

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

BUFBX vs. TWEIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
BUFBX Buffalo Flexible Income Fund	9.91%	10.37%	10.26%	7.42%	3.97%	29.97%	-2.27%	18.76%	-7.01%	13.20%
TWEIX American Century Equity Income Fund	10.31%	11.84%	10.51%	3.92%	-3.06%	16.83%	1.10%	24.14%	-3.77%	13.35%

Correlation

The correlation between BUFBX and TWEIX is 0.63, which is moderate. They share some common price drivers but move independently often enough to provide real diversification benefit when combined.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.63
Correlation (3Y) Calculated over the trailing 3-year period	0.74
Correlation (5Y) Calculated over the trailing 5-year period	0.82
Correlation (10Y) Calculated over the trailing 10-year period	0.84
Correlation (All Time) Calculated using the full available price history since Aug 12, 1994	0.82

The correlation between BUFBX and TWEIX shifts across timeframes, from 0.63 (1 year) to 0.84 (10 years), reflecting how their relationship changes across market environments.

Return for Risk

BUFBX vs. TWEIX — Risk / Return Rank

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

BUFBX

BUFBX Risk / Return Rank: 55
BUFBX Sharpe Ratio Rank: 43
BUFBX Sortino Ratio Rank: 41
BUFBX Omega Ratio Rank: 40
BUFBX Calmar Ratio Rank: 85
BUFBX Martin Ratio Rank: 67

TWEIX

TWEIX Risk / Return Rank: 67
TWEIX Sharpe Ratio Rank: 73
TWEIX Sortino Ratio Rank: 77
TWEIX Omega Ratio Rank: 65
TWEIX Calmar Ratio Rank: 67
TWEIX Martin Ratio Rank: 50

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.

BUFBX vs. TWEIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Buffalo Flexible Income Fund (BUFBX) and American Century Equity Income Fund (TWEIX). 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.

	BUFBX	TWEIX	Difference
Sharpe ratio: Return per unit of total volatility	1.44	1.88	-0.43
Sortino ratio: Return per unit of downside risk	2.04	2.84	-0.79
Omega ratio: Gain probability vs. loss probability	1.25	1.32	-0.07
Calmar ratio: Return relative to maximum drawdown	3.17	2.49	+0.68
Martin ratio: Return relative to average drawdown	9.91	8.12	+1.78

BUFBX vs. TWEIX - Sharpe Ratio Comparison

The current BUFBX Sharpe Ratio is 1.44, which is comparable to the TWEIX Sharpe Ratio of 1.88. The chart below compares the historical Sharpe Ratios of BUFBX and TWEIX, 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

BUFBX vs. TWEIX - Drawdown Comparison

The maximum BUFBX drawdown since its inception was -39.78%, roughly equal to the maximum TWEIX drawdown of -39.30%. Use the drawdown chart below to compare losses from any high point for BUFBX and TWEIX.

Drawdown Indicators

	BUFBX	TWEIX	Difference
Max Drawdown Largest peak-to-trough decline	-39.78%	-39.30%	-0.48%
Max Drawdown (1Y) Largest decline over 1 year	-4.45%	-6.43%	+1.98%
Max Drawdown (3Y) Largest decline over 3 years	-12.85%	-10.16%	-2.69%
Max Drawdown (5Y) Largest decline over 5 years	-14.67%	-13.69%	-0.98%
Max Drawdown (10Y) Largest decline over 10 years	-35.51%	-32.82%	-2.69%
Current Drawdown Current decline from peak	-2.79%	-0.65%	-2.14%
Average Drawdown Average peak-to-trough decline	-4.71%	-4.15%	-0.56%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.43%	1.97%	-0.54%

Volatility

BUFBX vs. TWEIX - Volatility Comparison

Buffalo Flexible Income Fund (BUFBX) has a higher volatility of 4.55% compared to American Century Equity Income Fund (TWEIX) at 2.60%. This indicates that BUFBX's price experiences larger fluctuations and is considered to be riskier than TWEIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	BUFBX	TWEIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.55%	2.60%	+1.95%
Volatility (6M) Calculated over the trailing 6-month period	7.72%	6.43%	+1.29%
Volatility (1Y) Calculated over the trailing 1-year period	9.79%	8.54%	+1.25%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	13.48%	10.75%	+2.73%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	15.60%	13.31%	+2.29%

BUFBX vs. TWEIX - Expense Ratio Comparison

BUFBX has a 1.01% expense ratio, which is higher than TWEIX's 0.94% expense ratio.

Dividends

BUFBX vs. TWEIX - Dividend Comparison

BUFBX's dividend yield for the trailing twelve months is around 8.29%, less than TWEIX's 9.56% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
BUFBX Buffalo Flexible Income Fund	8.29%	9.10%	3.77%	3.48%	4.16%	5.57%	3.33%	2.73%	6.01%	5.49%	2.39%	3.67%
TWEIX American Century Equity Income Fund	9.56%	10.35%	11.51%	8.02%	8.76%	6.83%	2.00%	7.38%	8.79%	11.95%	7.88%	10.49%

Frequently Asked Questions

Can I hold both BUFBX and TWEIX in my portfolio?

BUFBX and TWEIX have a correlation of 0.63, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, BUFBX or TWEIX?

BUFBX has higher volatility (4.55%) compared to TWEIX (2.60%). In terms of maximum drawdown, BUFBX dropped -39.78% vs TWEIX's -39.30%.

Which has better risk-adjusted returns?

TWEIX currently has the higher Sharpe Ratio (1.88 vs 1.44), 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.