FIOOX vs. BUFBX

Last updated Jun 4, 2026

FIOOX (Fidelity Series Large Cap Value Index Fund) and BUFBX (Buffalo Flexible Income Fund) are both Large Cap Value Equities funds. Over the past 10 years, FIOOX returned 11.18%/yr vs 10.00%/yr for BUFBX. Their correlation of 0.87 suggests significant overlap in exposure. FIOOX charges 0.00%/yr vs 1.01%/yr for BUFBX.

Performance

FIOOX vs. BUFBX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Fidelity Series Large Cap Value Index Fund (FIOOX) and Buffalo Flexible Income Fund (BUFBX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, FIOOX achieves a 14.32% return, which is significantly higher than BUFBX's 12.83% return. Over the past 10 years, FIOOX has outperformed BUFBX with an annualized return of 11.18%, while BUFBX has yielded a comparatively lower 10.00% annualized return.

FIOOX

• 1D: 0.77%
• 1M: 4.25%
• YTD: 14.32%
• 6M: 14.94%
• 1Y: 28.42%
• 3Y*: 18.65%
• 5Y*: 10.50%
• 10Y*: 11.18%

BUFBX

• 1D: 0.57%
• 1M: 3.64%
• YTD: 12.83%
• 6M: 12.77%
• 1Y: 19.88%
• 3Y*: 13.91%
• 5Y*: 11.23%
• 10Y*: 10.00%

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

FIOOX vs. BUFBX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
FIOOX Fidelity Series Large Cap Value Index Fund	14.32%	15.95%	14.34%	11.60%	-7.56%	25.23%	2.85%	26.57%	-8.28%	11.06%
BUFBX Buffalo Flexible Income Fund	12.83%	10.37%	10.26%	7.42%	3.97%	29.97%	-2.27%	18.76%	-7.01%	13.20%

Correlation

The correlation between FIOOX and BUFBX is 0.57, 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	0.57
Correlation (3Y) Calculated over the trailing 3-year period	0.76
Correlation (5Y) Calculated over the trailing 5-year period	0.83
Correlation (10Y) Calculated over the trailing 10-year period	0.86
Correlation (All Time) Calculated using the full available price history since Nov 20, 2013	0.87

Over the past year, the correlation between FIOOX and BUFBX has dropped to 0.57 - well below their long-term average of 0.87, suggesting their price drivers have been diverging.

Return for Risk

FIOOX vs. BUFBX — Risk / Return Rank

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

FIOOX

FIOOX Risk / Return Rank: 83
FIOOX Sharpe Ratio Rank: 84
FIOOX Sortino Ratio Rank: 81
FIOOX Omega Ratio Rank: 74
FIOOX Calmar Ratio Rank: 88
FIOOX Martin Ratio Rank: 90

BUFBX

BUFBX Risk / Return Rank: 71
BUFBX Sharpe Ratio Rank: 60
BUFBX Sortino Ratio Rank: 59
BUFBX Omega Ratio Rank: 52
BUFBX Calmar Ratio Rank: 97
BUFBX Martin Ratio Rank: 89

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.

FIOOX vs. BUFBX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Fidelity Series Large Cap Value Index Fund (FIOOX) and Buffalo Flexible Income Fund (BUFBX). 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.

	FIOOX	BUFBX	Difference
Sharpe ratio: Return per unit of total volatility	2.71	2.28	+0.43
Sortino ratio: Return per unit of downside risk	3.81	3.24	+0.58
Omega ratio: Gain probability vs. loss probability	1.49	1.40	+0.09
Calmar ratio: Return relative to maximum drawdown	4.31	7.18	-2.86
Martin ratio: Return relative to average drawdown	18.02	17.54	+0.48
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

FIOOX vs. BUFBX - Sharpe Ratio Comparison

The current FIOOX Sharpe Ratio is 2.71, which is comparable to the BUFBX Sharpe Ratio of 2.28. The chart below compares the historical Sharpe Ratios of FIOOX and BUFBX, 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

	FIOOX	BUFBX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.71	2.28	+0.43
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.71	0.84	-0.13
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.65	0.64	0.00
Sharpe Ratio (All Time) Calculated using the full available price history	0.61	0.59	+0.02

Drawdowns

FIOOX vs. BUFBX - Drawdown Comparison

The maximum FIOOX drawdown since its inception was -38.31%, roughly equal to the maximum BUFBX drawdown of -39.78%. Use the drawdown chart below to compare losses from any high point for FIOOX and BUFBX.

Drawdown Indicators

	FIOOX	BUFBX	Difference
Max Drawdown Largest peak-to-trough decline	-38.31%	-39.78%	+1.47%
Max Drawdown (1Y) Largest decline over 1 year	-6.80%	-2.83%	-3.97%
Max Drawdown (3Y) Largest decline over 3 years	-15.66%	-12.85%	-2.81%
Max Drawdown (5Y) Largest decline over 5 years	-19.02%	-14.67%	-4.35%
Max Drawdown (10Y) Largest decline over 10 years	-38.31%	-35.51%	-2.80%
Current Drawdown Current decline from peak	0.00%	-0.22%	+0.22%
Average Drawdown Average peak-to-trough decline	-4.05%	-4.72%	+0.67%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.62%	1.16%	+0.46%

Volatility

FIOOX vs. BUFBX - Volatility Comparison

Fidelity Series Large Cap Value Index Fund (FIOOX) and Buffalo Flexible Income Fund (BUFBX) have volatilities of 3.06% and 3.06%, 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

	FIOOX	BUFBX	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.06%	3.06%	0.00%
Volatility (6M) Calculated over the trailing 6-month period	8.16%	6.61%	+1.55%
Volatility (1Y) Calculated over the trailing 1-year period	10.82%	8.93%	+1.89%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	14.88%	13.40%	+1.48%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	17.38%	15.60%	+1.78%

FIOOX vs. BUFBX - Expense Ratio Comparison

FIOOX has a 0.00% expense ratio, which is lower than BUFBX's 1.01% expense ratio.

Dividends

FIOOX vs. BUFBX - Dividend Comparison

FIOOX's dividend yield for the trailing twelve months is around 3.09%, less than BUFBX's 7.99% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
BUFBX Buffalo Flexible Income Fund	7.99%	9.10%	3.77%	3.48%	4.16%	5.57%	3.33%	2.73%	6.01%	5.49%	2.39%	3.67%
FIOOX Fidelity Series Large Cap Value Index Fund	3.09%	3.66%	3.30%	4.31%	4.39%	6.12%	2.59%	6.82%	4.99%	1.74%	2.48%	6.77%

Frequently Asked Questions

Can I hold both FIOOX and BUFBX in my portfolio?

FIOOX and BUFBX have a correlation of 0.57, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, FIOOX or BUFBX?

BUFBX has higher volatility (3.06%) compared to FIOOX (3.06%). In terms of maximum drawdown, FIOOX dropped -38.31% vs BUFBX's -39.78%.

Which has better risk-adjusted returns?

FIOOX currently has the higher Sharpe Ratio (2.71 vs 2.28), 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.