BUFTX vs. NEEIX
BUFTX (Buffalo Discovery Fund) and NEEIX (Needham Growth Fund Institutional Class) are both Mid Cap Growth Equities funds. Over the past 5 years, BUFTX returned -2.05%/yr vs 10.88%/yr for NEEIX. Their correlation of 0.84 means they have usually moved in the same direction. BUFTX charges 1.00%/yr vs 1.21%/yr for NEEIX.
Performance
BUFTX vs. NEEIX - Performance Comparison
Loading charts...
Returns By Period
In the year-to-date period, BUFTX achieves a -2.93% return, which is significantly lower than NEEIX's 38.99% return.
BUFTX
- 1D
- 2.42%
- 1M
- -0.87%
- 6M
- 1.00%
- YTD
- -2.93%
- 1Y
- -8.70%
- 3Y*
- 2.96%
- 5Y*
- -2.05%
- 10Y*
- 7.17%
- ALL TIME*
- 8.08%
NEEIX
- 1D
- 2.27%
- 1M
- -7.20%
- 6M
- 20.42%
- YTD
- 38.99%
- 1Y
- 54.45%
- 3Y*
- 21.63%
- 5Y*
- 10.88%
- 10Y*
- —
- ALL TIME*
- 15.33%
Liquidity Comparison
| Position | Avg. Volume Value (2W) | Avg. Volume Value (1M) | Avg. Volume Value (3M) |
|---|---|---|---|
| $0.00 | $0.00 | $0.00 | |
| $0.00 | $0.00 | $0.00 |
BUFTX vs. NEEIX - Yearly Performance Comparison
| 2026 (YTD) | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | |
|---|---|---|---|---|---|---|---|---|---|---|
BUFTX Buffalo Discovery Fund | -2.93% | -1.83% | 5.31% | 24.30% | -28.78% | 11.55% | 33.90% | 31.62% | -6.52% | 25.43% |
NEEIX Needham Growth Fund Institutional Class | 38.99% | 9.32% | 19.26% | 27.30% | -33.26% | 28.13% | 42.39% | 43.15% | -10.13% | 8.47% |
Correlation
The correlation between BUFTX and NEEIX is 0.74, which is moderate. They have sometimes moved together and sometimes differently, sharing some price drivers without tracking each other closely.
| Correlation | |
|---|---|
Correlation (1Y) Focuses on recent behavior, but can change the most. | 0.74 |
Correlation (3Y) Balances recent behavior with more history. | 0.77 |
Correlation (5Y) Shows whether the relationship held over a longer period. | 0.83 |
Correlation (All Time) Calculated using the full available price history since Jan 3, 2017 | 0.84 |
The correlation between BUFTX and NEEIX has been stable across timeframes, ranging from 0.74 to 0.84 - a consistent structural relationship.
Compare stocks, funds, or ETFs
Search for stocks, ETFs, and funds for a quick comparison or use the comparison tool for more options.
Return for Risk
BUFTX vs. NEEIX — Risk / Return Rank
BUFTX
NEEIX
BUFTX vs. NEEIX - Risk-Adjusted Trends Comparison
This table presents a comparison of risk-adjusted performance metrics for Buffalo Discovery Fund (BUFTX) and Needham Growth Fund Institutional Class (NEEIX). 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.
| BUFTX | NEEIX | Difference | |
|---|---|---|---|
| Sharpe ratioReturn per unit of total volatility | -2.18 | ||
| Sortino ratioReturn per unit of downside risk | -2.76 | ||
| Omega ratioGain probability vs. loss probability | 0.95 | 1.29 | -0.34 |
| Calmar ratioReturn relative to maximum drawdown | -0.39 | 2.47 | -2.86 |
| Martin ratioReturn relative to average drawdown | -0.85 | 9.95 | -10.80 |
Loading charts...
Drawdowns
BUFTX vs. NEEIX - Drawdown Comparison
The maximum BUFTX drawdown since its inception was -60.45%, which is greater than NEEIX's maximum drawdown of -43.11%. Use the drawdown chart below to compare losses from any high point for BUFTX and NEEIX.
Loading charts...
Drawdown Indicators
| BUFTX | NEEIX | Difference | |
|---|---|---|---|
Max DrawdownLargest peak-to-trough decline | -60.45% | -43.11% | -17.34% |
Max Drawdown (1Y)Largest decline over 1 year | -17.96% | -23.12% | +5.16% |
Max Drawdown (3Y)Largest decline over 3 years | -22.10% | -36.13% | +14.03% |
Max Drawdown (5Y)Largest decline over 5 years | -36.36% | -43.11% | +6.75% |
Max Drawdown (10Y)Largest decline over 10 years | -36.36% | — | — |
Current DrawdownCurrent decline from peak | -13.91% | -16.09% | +2.18% |
Average DrawdownAverage peak-to-trough decline | -11.34% | -10.83% | -0.51% |
Ulcer IndexDepth and duration of drawdowns from previous peaks | 8.32% | 5.72% | +2.60% |
Volatility
BUFTX vs. NEEIX - Volatility Comparison
The current volatility for Buffalo Discovery Fund (BUFTX) is 6.19%, while Needham Growth Fund Institutional Class (NEEIX) has a volatility of 11.80%. This indicates that BUFTX experiences smaller price fluctuations and is considered to be less risky than NEEIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.
Loading charts...
Volatility by Period
| BUFTX | NEEIX | Difference | |
|---|---|---|---|
Volatility (1M)Calculated over the trailing 1-month period | 6.19% | 11.80% | -5.61% |
Volatility (6M)Calculated over the trailing 6-month period | 13.71% | 26.81% | -13.10% |
Volatility (1Y)Calculated over the trailing 1-year period | 16.96% | 32.47% | -15.51% |
Volatility (5Y)Calculated over the trailing 5-year period, annualized | 21.32% | 29.45% | -8.13% |
Volatility (10Y)Calculated over the trailing 10-year period, annualized | 20.47% | 26.32% | -5.85% |
BUFTX vs. NEEIX - Expense Ratio Comparison
BUFTX has a 1.00% expense ratio, which is lower than NEEIX's 1.21% expense ratio.
Dividends
BUFTX vs. NEEIX - Dividend Comparison
BUFTX's dividend yield for the trailing twelve months is around 21.78%, more than NEEIX's 5.15% yield.
| Position | TTM | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
BUFTX Buffalo Discovery Fund | 21.78% | 21.15% | 10.00% | 0.00% | 7.08% | 15.11% | 7.98% | 14.81% | 7.01% | 4.64% | 0.00% | 7.56% |
NEEIX Needham Growth Fund Institutional Class | 5.15% | 7.16% | 7.48% | 0.00% | 1.72% | 6.70% | 5.58% | 11.09% | 17.58% | 9.64% | 0.00% | 0.00% |
Frequently Asked Questions
BUFTX and NEEIX have a correlation of 0.74, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.
NEEIX has higher volatility (11.80%) compared to BUFTX (6.19%). In terms of maximum drawdown, BUFTX dropped -60.45% vs NEEIX's -43.11%.
NEEIX currently has the higher Sharpe Ratio (1.76 vs -0.42), 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.
Find the right allocation for BUFTX and NEEIX
Add both to a portfolio and optimize allocations for your target — whether that's maximizing returns, minimizing drawdowns, or balancing risk across holdings.
Open Portfolio Optimizer