NESIX vs. BUFOX

Last updated Jun 23, 2026

NESIX (Needham Small Cap Growth Fund Institutional) and BUFOX (Buffalo Early Stage Growth Fund) are both Small Cap Growth Equities funds. Over the past 5 years, NESIX returned 10.69%/yr vs -0.95%/yr for BUFOX. Their correlation of 0.84 suggests significant overlap in exposure. NESIX charges 1.18%/yr vs 1.46%/yr for BUFOX.

Performance

NESIX vs. BUFOX - Performance Comparison

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

Returns By Period

In the year-to-date period, NESIX achieves a 84.62% return, which is significantly higher than BUFOX's 17.05% return.

NESIX

• 1D: 3.45%
• 1M: 10.97%
• YTD: 84.62%
• 6M: 79.78%
• 1Y: 126.23%
• 3Y*: 33.61%
• 5Y*: 10.69%
• 10Y*: —

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%

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

NESIX vs. BUFOX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
NESIX Needham Small Cap Growth Fund Institutional	84.62%	11.16%	13.47%	5.85%	-29.71%	11.36%	73.06%	55.28%	-4.87%	12.63%
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%

Correlation

The correlation between NESIX and BUFOX is 0.82, 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	0.82
Correlation (3Y) Calculated over the trailing 3-year period	0.83
Correlation (5Y) Calculated over the trailing 5-year period	0.86
Correlation (All Time) Calculated using the full available price history since Jan 3, 2017	0.84

The correlation between NESIX and BUFOX has been stable across timeframes, ranging from 0.82 to 0.86 - a consistent structural relationship.

Return for Risk

NESIX vs. BUFOX — Risk / Return Rank

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

NESIX

NESIX Risk / Return Rank: 95
NESIX Sharpe Ratio Rank: 99
NESIX Sortino Ratio Rank: 92
NESIX Omega Ratio Rank: 87
NESIX Calmar Ratio Rank: 98
NESIX Martin Ratio Rank: 98

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

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.

NESIX vs. BUFOX - Risk-Adjusted Trends Comparison

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

	NESIX	BUFOX	Difference
Sharpe ratio: Return per unit of total volatility	3.96	1.41	+2.55
Sortino ratio: Return per unit of downside risk	4.30	2.03	+2.28
Omega ratio: Gain probability vs. loss probability	1.56	1.24	+0.32
Calmar ratio: Return relative to maximum drawdown	7.25	2.07	+5.18
Martin ratio: Return relative to average drawdown	29.54	6.19	+23.35

NESIX vs. BUFOX - Sharpe Ratio Comparison

The current NESIX Sharpe Ratio is 3.96, which is higher than the BUFOX Sharpe Ratio of 1.41. The chart below compares the historical Sharpe Ratios of NESIX and BUFOX, 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

NESIX vs. BUFOX - Drawdown Comparison

The maximum NESIX drawdown since its inception was -49.61%, smaller than the maximum BUFOX drawdown of -69.71%. Use the drawdown chart below to compare losses from any high point for NESIX and BUFOX.

Drawdown Indicators

	NESIX	BUFOX	Difference
Max Drawdown Largest peak-to-trough decline	-49.61%	-69.71%	+20.10%
Max Drawdown (1Y) Largest decline over 1 year	-17.12%	-15.52%	-1.60%
Max Drawdown (3Y) Largest decline over 3 years	-35.21%	-24.62%	-10.59%
Max Drawdown (5Y) Largest decline over 5 years	-49.61%	-43.17%	-6.44%
Max Drawdown (10Y) Largest decline over 10 years	—	-43.17%	—
Current Drawdown Current decline from peak	0.00%	-9.98%	+9.98%
Average Drawdown Average peak-to-trough decline	-14.93%	-16.04%	+1.11%
Ulcer Index Depth and duration of drawdowns from previous peaks	4.19%	5.18%	-0.99%

Volatility

NESIX vs. BUFOX - Volatility Comparison

Needham Small Cap Growth Fund Institutional (NESIX) has a higher volatility of 12.03% compared to Buffalo Early Stage Growth Fund (BUFOX) at 7.75%. This indicates that NESIX's price experiences larger fluctuations and is considered to be riskier than BUFOX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	NESIX	BUFOX	Difference
Volatility (1M) Calculated over the trailing 1-month period	12.03%	7.75%	+4.28%
Volatility (6M) Calculated over the trailing 6-month period	22.42%	16.77%	+5.65%
Volatility (1Y) Calculated over the trailing 1-year period	31.32%	22.76%	+8.56%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	29.58%	22.93%	+6.65%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	26.57%	22.45%	+4.12%

NESIX vs. BUFOX - Expense Ratio Comparison

NESIX has a 1.18% expense ratio, which is lower than BUFOX's 1.46% expense ratio.

Dividends

NESIX vs. BUFOX - Dividend Comparison

NESIX has not paid dividends to shareholders, while BUFOX's dividend yield for the trailing twelve months is around 4.36%.

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%
NESIX Needham Small Cap Growth Fund Institutional	0.00%	0.00%	0.00%	0.00%	3.93%	23.92%	13.26%	8.25%	21.96%	8.89%	0.00%	0.00%

Frequently Asked Questions

Can I hold both NESIX and BUFOX in my portfolio?

NESIX and BUFOX have a correlation of 0.82, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, NESIX or BUFOX?

NESIX has higher volatility (12.03%) compared to BUFOX (7.75%). In terms of maximum drawdown, NESIX dropped -49.61% vs BUFOX's -69.71%.

Which has better risk-adjusted returns?

NESIX currently has the higher Sharpe Ratio (3.96 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.