BUFOX vs. NEAIX

Last updated Jun 23, 2026

BUFOX (Buffalo Early Stage Growth Fund) and NEAIX (Needham Aggressive Growth Fund Institutional Class) are both Small Cap Growth Equities funds. Over the past 5 years, BUFOX returned -0.95%/yr vs 24.40%/yr for NEAIX. Their correlation of 0.83 suggests significant overlap in exposure. BUFOX charges 1.46%/yr vs 1.20%/yr for NEAIX.

Performance

BUFOX vs. NEAIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Buffalo Early Stage Growth Fund (BUFOX) and Needham Aggressive Growth Fund Institutional Class (NEAIX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, BUFOX achieves a 17.05% return, which is significantly lower than NEAIX's 62.37% return.

BUFOX

• 1D: 2.70%
• 1M: 7.70%
• YTD: 17.05%
• 6M: 13.21%
• 1Y: 32.67%
• 3Y*: 8.32%
• 5Y*: -0.95%
• 10Y*: 11.24%

NEAIX

• 1D: 3.36%
• 1M: 10.07%
• YTD: 62.37%
• 6M: 59.51%
• 1Y: 93.45%
• 3Y*: 38.53%
• 5Y*: 24.40%
• 10Y*: —

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

BUFOX vs. NEAIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
BUFOX Buffalo Early Stage Growth Fund	17.05%	3.09%	7.52%	9.83%	-30.78%	7.43%	47.85%	34.06%	-3.78%	27.03%
NEAIX Needham Aggressive Growth Fund Institutional Class	62.37%	26.99%	14.86%	38.37%	-27.02%	38.46%	52.49%	44.68%	-15.64%	10.07%

Correlation

The correlation between BUFOX and NEAIX is 0.84, 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	0.84
Correlation (3Y) Calculated over the trailing 3-year period	0.82
Correlation (5Y) Calculated over the trailing 5-year period	0.84
Correlation (All Time) Calculated using the full available price history since Jan 3, 2017	0.83

The correlation between BUFOX and NEAIX has been stable across timeframes, ranging from 0.82 to 0.84 - a consistent structural relationship.

Return for Risk

BUFOX vs. NEAIX — Risk / Return Rank

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

BUFOX

BUFOX Risk / Return Rank: 28
BUFOX Sharpe Ratio Rank: 28
BUFOX Sortino Ratio Rank: 27
BUFOX Omega Ratio Rank: 23
BUFOX Calmar Ratio Rank: 33
BUFOX Martin Ratio Rank: 28

NEAIX

NEAIX Risk / Return Rank: 93
NEAIX Sharpe Ratio Rank: 97
NEAIX Sortino Ratio Rank: 87
NEAIX Omega Ratio Rank: 84
NEAIX Calmar Ratio Rank: 97
NEAIX Martin Ratio Rank: 97

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.

BUFOX vs. NEAIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Buffalo Early Stage Growth Fund (BUFOX) and Needham Aggressive Growth Fund Institutional Class (NEAIX). 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.

	BUFOX	NEAIX	Difference
Sharpe ratio: Return per unit of total volatility	1.41	3.40	-1.99
Sortino ratio: Return per unit of downside risk	2.03	3.89	-1.86
Omega ratio: Gain probability vs. loss probability	1.24	1.52	-0.29
Calmar ratio: Return relative to maximum drawdown	2.07	6.65	-4.58
Martin ratio: Return relative to average drawdown	6.19	26.15	-19.96

BUFOX vs. NEAIX - Sharpe Ratio Comparison

The current BUFOX Sharpe Ratio is 1.41, which is lower than the NEAIX Sharpe Ratio of 3.40. The chart below compares the historical Sharpe Ratios of BUFOX and NEAIX, 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

BUFOX vs. NEAIX - Drawdown Comparison

The maximum BUFOX drawdown since its inception was -69.71%, which is greater than NEAIX's maximum drawdown of -35.93%. Use the drawdown chart below to compare losses from any high point for BUFOX and NEAIX.

Drawdown Indicators

	BUFOX	NEAIX	Difference
Max Drawdown Largest peak-to-trough decline	-69.71%	-35.93%	-33.78%
Max Drawdown (1Y) Largest decline over 1 year	-15.52%	-13.98%	-1.54%
Max Drawdown (3Y) Largest decline over 3 years	-24.62%	-28.21%	+3.59%
Max Drawdown (5Y) Largest decline over 5 years	-43.17%	-35.93%	-7.24%
Max Drawdown (10Y) Largest decline over 10 years	-43.17%	—	—
Current Drawdown Current decline from peak	-9.98%	0.00%	-9.98%
Average Drawdown Average peak-to-trough decline	-16.04%	-8.57%	-7.47%
Ulcer Index Depth and duration of drawdowns from previous peaks	5.18%	3.55%	+1.63%

Volatility

BUFOX vs. NEAIX - Volatility Comparison

The current volatility for Buffalo Early Stage Growth Fund (BUFOX) is 7.75%, while Needham Aggressive Growth Fund Institutional Class (NEAIX) has a volatility of 11.79%. This indicates that BUFOX experiences smaller price fluctuations and is considered to be less risky than NEAIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	BUFOX	NEAIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	7.75%	11.79%	-4.04%
Volatility (6M) Calculated over the trailing 6-month period	16.77%	22.24%	-5.47%
Volatility (1Y) Calculated over the trailing 1-year period	22.76%	27.29%	-4.53%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	22.93%	24.92%	-1.99%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	22.45%	24.74%	-2.29%

BUFOX vs. NEAIX - Expense Ratio Comparison

BUFOX has a 1.46% expense ratio, which is higher than NEAIX's 1.20% expense ratio.

Dividends

BUFOX vs. NEAIX - Dividend Comparison

BUFOX's dividend yield for the trailing twelve months is around 4.36%, more than NEAIX's 1.24% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
BUFOX Buffalo Early Stage Growth Fund	4.36%	5.10%	0.00%	0.00%	1.20%	15.83%	11.19%	4.77%	14.50%	20.01%	8.35%	8.53%
NEAIX Needham Aggressive Growth Fund Institutional Class	1.24%	2.01%	0.00%	0.00%	0.00%	6.84%	3.80%	10.42%	16.35%	5.14%	0.00%	0.00%

Frequently Asked Questions

Can I hold both BUFOX and NEAIX in my portfolio?

BUFOX and NEAIX have a correlation of 0.84, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, BUFOX or NEAIX?

NEAIX has higher volatility (11.79%) compared to BUFOX (7.75%). In terms of maximum drawdown, BUFOX dropped -69.71% vs NEAIX's -35.93%.

Which has better risk-adjusted returns?

NEAIX currently has the higher Sharpe Ratio (3.40 vs 1.41), 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.