OBSOX Performance — Oberweis Small-Cap Opportunities Fund, Investor Class
Data updated: 2026-08-28
OBSOX returned +42.36% year to date and +59.38% over one year to Jun 2026. Annualised returns are +24.21% over 3 years and +17.31% over 5 years. The fund beat its US Small Growth category average: $100 invested three years ago grew to $192, against $156 for the category, and to $159 over one year, against $132. Volatility over the past three years was 20.97% a year. In the 12 months to Jun 2026 the fund took in a net $320.8M, and assets reached $2.84B.
OBSOX Growth of $100
What $100 invested in Oberweis Small-Cap Opportunities Fund grew to, compounded from monthly returns reported on SEC Form N-PORT, against the US Small Growth category average over the same months.
| Period | OBSOX | Category average |
|---|---|---|
| 1 year (Jul 2025 – Jun 2026) | $159 | $132 |
| 3 years (Jul 2023 – Jun 2026) | $192 | $156 |
| 5 years (Jul 2021 – Jun 2026) | $222 | $127 |
| Since data start (Jul 2019 – Jun 2026) | $384 | $203 |
OBSOX Trailing Returns
Total returns to Jun 2026, from SEC N-PORT.
| Period | Total return |
|---|---|
| YTD | +42.36% |
| 1 year | +59.38% |
| 3 years (annualised) | +24.21% |
| 5 years (annualised) | +17.31% |
OBSOX Annual Returns
Calendar-year total returns of Oberweis Small-Cap Opportunities Fund, compounded from monthly SEC N-PORT returns. Partial years show the months covered.
| Year | Total return |
|---|---|
| 2026 (Jan–Jun) | +42.36% |
| 2025 | +14.28% |
| 2024 | +16.14% |
| 2023 | +15.81% |
| 2022 | −11.17% |
| 2021 | +43.57% |
| 2020 | +32.47% |
| 2019 (Jul–Dec) | +3.76% |
OBSOX Monthly Returns
Monthly total returns as reported on SEC Form N-PORT.
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2026 | +1.5% | +7.5% | −5.0% | +19.5% | +5.6% | +8.8% | — | — | — | — | — | — |
| 2025 | +6.2% | −7.6% | −9.5% | +1.1% | +5.3% | +7.9% | −0.5% | +5.8% | +2.7% | +1.1% | +2.4% | +0.1% |
| 2024 | −0.8% | +6.4% | +4.2% | −3.4% | +8.4% | −0.3% | +1.9% | +1.3% | +1.6% | −4.6% | +7.4% | −5.9% |
| 2023 | +11.4% | +0.6% | −0.7% | −6.0% | +0.4% | +8.9% | +5.0% | −3.6% | −5.9% | −8.5% | +8.8% | +6.9% |
| 2022 | −12.0% | +3.8% | +1.6% | −8.3% | −0.1% | −8.7% | +14.2% | −1.6% | −7.4% | +11.8% | +6.2% | −7.4% |
| 2021 | +3.3% | +11.0% | +1.4% | +4.5% | +0.5% | +2.8% | −0.2% | +5.5% | −2.1% | +5.5% | +1.3% | +3.6% |
| 2020 | 0.0% | −8.5% | −18.8% | +10.7% | +11.2% | +6.2% | +8.1% | +1.9% | −1.4% | +1.7% | +14.0% | +8.3% |
| 2019 | — | — | — | — | — | — | +1.1% | −6.2% | +0.3% | +2.5% | +5.2% | +1.2% |
OBSOX Risk
Risk measures from monthly returns over Jul 2023 – Jun 2026.
- 3-year volatility (annualised): 20.97%
- 3-year Sharpe ratio: 0.94 (vs 4.5% risk-free rate)
- Best month: +19.50% (Apr 2026)
- Worst month: −9.48% (Mar 2025)
OBSOX Fund Flows
Monthly money in and out of Oberweis Small-Cap Opportunities Fund, from SEC Form N-PORT.
- 12-month net flow: $320.8M
- 12-month gross sales (incl. reinvestments): $859.9M
- Sales ÷ redemptions: 1.60×
| Month | Sales | Redemptions | Net flow |
|---|---|---|---|
| Jun 2026 | $105.3M | $58.3M | $47.0M |
| May 2026 | $79.8M | $60.8M | $19.0M |
| Apr 2026 | $67.2M | $53.3M | $13.9M |
| Mar 2026 | $117.7M | $47.7M | $70.0M |
| Feb 2026 | $48.8M | $40.3M | $8.6M |
| Jan 2026 | $81.5M | $42.8M | $38.7M |
| Dec 2025 | $53.7M | $31.9M | $21.8M |
| Nov 2025 | $75.2M | $27.2M | $48.1M |
| Oct 2025 | $64.0M | $34.8M | $29.2M |
| Sep 2025 | $45.2M | $35.6M | $9.6M |
| Aug 2025 | $47.6M | $62.9M | −$15.3M |
| Jul 2025 | $73.8M | $43.5M | $30.3M |
OBSOX Assets Under Management
Net assets of Oberweis Small-Cap Opportunities Fund by report date, from SEC N-PORT filings.
| Report date | Net assets |
|---|---|
| 2026-06-30 | $2.84B |
| 2026-03-31 | $2.01B |
| 2025-12-31 | $1.82B |
| 2025-09-30 | $1.66B |
| 2025-06-30 | $1.51B |
| 2025-03-31 | $1.37B |
| 2024-12-31 | $1.41B |
| 2024-09-30 | $1.32B |
| 2024-06-30 | $1.05B |
| 2024-03-31 | $826.92M |
| 2023-12-31 | $514.93M |
| 2023-09-30 | $416.71M |
For information only. Not investment advice: figures are as reported in SEC filings and may contain errors or be out of date. Past performance does not guarantee future results.