WSMNX Performance — William Blair Small-Mid Cap Growth Fund, Class N
Data updated: 2026-08-14
WSMNX returned +15.34% year to date and +23.84% over one year to Jun 2026. Annualised returns are +10.71% over 3 years and +3.14% over 5 years. Against its US Mid-Cap Growth category average the fund came out behind over three years but ahead over one: $100 invested three years ago grew to $136, against $152 for the category, and to $124 over one year, against $118. Volatility over the past three years was 17.75% a year. In the 12 months to Jun 2026 the fund lost a net $373.1M, and assets reached $1.32B.
WSMNX Growth of $100
What $100 invested in William Blair Small-Mid Cap Growth Fund grew to, compounded from monthly returns reported on SEC Form N-PORT, against the US Mid-Cap Growth category average over the same months.
| Period | WSMNX | Category average |
|---|---|---|
| 1 year (Jul 2025 – Jun 2026) | $124 | $118 |
| 3 years (Jul 2023 – Jun 2026) | $136 | $152 |
| 5 years (Jul 2021 – Jun 2026) | $117 | $129 |
| Since data start (Jul 2019 – Jun 2026) | $175 | $203 |
WSMNX Trailing Returns
Total returns to Jun 2026, from SEC N-PORT.
| Period | Total return |
|---|---|
| YTD | +15.34% |
| 1 year | +23.84% |
| 3 years (annualised) | +10.71% |
| 5 years (annualised) | +3.14% |
WSMNX Annual Returns
Calendar-year total returns of William Blair Small-Mid Cap Growth Fund, compounded from monthly SEC N-PORT returns. Partial years show the months covered.
| Year | Total return |
|---|---|
| 2026 (Jan–Jun) | +15.34% |
| 2025 | +0.37% |
| 2024 | +11.24% |
| 2023 | +17.63% |
| 2022 | −23.12% |
| 2021 | +8.29% |
| 2020 | +32.05% |
| 2019 (Jul–Dec) | +4.93% |
WSMNX 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 | +2.6% | +0.2% | −4.7% | +9.6% | +3.9% | +3.4% | — | — | — | — | — | — |
| 2025 | +3.3% | −6.9% | −8.1% | −2.9% | +3.5% | +5.1% | +0.6% | +3.5% | +1.3% | +0.5% | +2.5% | −1.3% |
| 2024 | −1.9% | +9.4% | +1.4% | −8.0% | +3.2% | −2.1% | +6.1% | +0.8% | +1.7% | −1.6% | +8.9% | −5.7% |
| 2023 | +10.6% | −2.7% | −2.1% | −0.6% | −1.2% | +8.0% | +2.3% | −3.2% | −5.2% | −6.8% | +9.4% | +10.2% |
| 2022 | −12.6% | +2.0% | +1.4% | −11.5% | −3.1% | −8.0% | +11.1% | −3.4% | −7.9% | +7.5% | +6.5% | −4.8% |
| 2021 | +1.0% | +4.6% | −1.6% | +4.4% | −3.9% | +3.5% | +0.2% | +1.9% | −3.3% | +6.2% | −5.8% | +1.4% |
| 2020 | +0.8% | −6.0% | −16.0% | +13.7% | +10.9% | +0.3% | +4.5% | +5.3% | −1.6% | +0.3% | +13.5% | +6.4% |
| 2019 | — | — | — | — | — | — | +2.6% | +0.2% | −2.0% | +0.1% | +4.4% | −0.3% |
WSMNX Risk
Risk measures from monthly returns over Jul 2023 – Jun 2026.
- 3-year volatility (annualised): 17.75%
- 3-year Sharpe ratio: 0.35 (vs 4.5% risk-free rate)
- Best month: +10.15% (Dec 2023)
- Worst month: −8.05% (Mar 2025)
WSMNX Fund Flows
Monthly money in and out of William Blair Small-Mid Cap Growth Fund, from SEC Form N-PORT.
- 12-month net flow: −$373.1M
- 12-month gross sales (incl. reinvestments): $190.7M
- Sales ÷ redemptions: 0.34×
| Month | Sales | Redemptions | Net flow |
|---|---|---|---|
| Jun 2026 | $62.6M | $33.3M | $29.4M |
| May 2026 | $6.2M | $27.4M | −$21.2M |
| Apr 2026 | $9.3M | $26.5M | −$17.2M |
| Mar 2026 | $6.9M | $14.9M | −$8.0M |
| Feb 2026 | $6.4M | $64.1M | −$57.8M |
| Jan 2026 | $6.3M | $47.4M | −$41.1M |
| Dec 2025 | $50.6M | $84.4M | −$33.8M |
| Nov 2025 | $5.9M | $60.3M | −$54.4M |
| Oct 2025 | $4.9M | $59.5M | −$54.6M |
| Sep 2025 | $5.7M | $29.8M | −$24.1M |
| Aug 2025 | $5.8M | $40.7M | −$34.9M |
| Jul 2025 | $20.3M | $75.6M | −$55.3M |
WSMNX Assets Under Management
Net assets of William Blair Small-Mid Cap Growth Fund by report date, from SEC N-PORT filings.
| Report date | Net assets |
|---|---|
| 2026-06-30 | $1.32B |
| 2026-03-31 | $1.13B |
| 2025-12-31 | $1.25B |
| 2025-09-30 | $1.41B |
| 2025-06-30 | $1.44B |
| 2025-03-31 | $1.47B |
| 2024-12-31 | $1.89B |
| 2024-09-30 | $2.01B |
| 2024-06-30 | $1.86B |
| 2024-03-31 | $2.04B |
| 2023-12-31 | $2.00B |
| 2023-09-30 | $1.90B |
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.