BLAIR WILLIAM & CO/IL
All 13F Filings
- Location
- Chicago, IL
- Most recent 13F
- Q4 2025
- Holdings value ($000)
- 37,259,506
- Description
- Chicago Illinois based durable growth focused equity allocator with a structured investment organization and a mandate specific and implementation minded investment mandate. The approach emphasizes durable growth thesis development, fundamental research depth, and concentrated position governance for high conviction growth portfolios. The process prioritizes downside control, mandate clarity, and consistent execution standards through liquidity aware implementation and risk accountability.
- Website
- https://www.williamblair.com/
- Founded
- 1935
- Chairman
- —
- CEO
- John Ettelson
- All SEC filings
- View on sec.gov
Sector allocation over time (stocks only)
Stacked by quarter. Hover to see detailed sector breakdown for any quarter.
| Quarter | Date Filed | Holdings | Value ($000) | Form Type | Name |
|---|---|---|---|---|---|
| Q4 2025 | 2/17/2026 | 1,867 | 37,259,506 | 13F-HR | BLAIR WILLIAM & CO/IL |
| Q3 2025 | 11/12/2025 | 1,844 | 37,569,258 | 13F-HR | BLAIR WILLIAM & CO/IL |
| Q2 2025 | 7/24/2025 | 1,824 | 36,002,455 | 13F-HR | BLAIR WILLIAM & CO/IL |
| Q1 2025 | 5/9/2025 | 1,801 | 33,156,793 | 13F-HR | BLAIR WILLIAM & CO/IL |
| Q4 2024 | 2/12/2025 | 1,816 | 34,378,594 | 13F-HR | BLAIR WILLIAM & CO/IL |
| Q3 2024 | 11/12/2024 | 1,821 | 34,050,188 | 13F-HR | BLAIR WILLIAM & CO/IL |
| Q2 2024 | 8/12/2024 | 1,822 | 32,421,065 | 13F-HR | BLAIR WILLIAM & CO/IL |
| Q1 2024 | 5/9/2024 | 1,787 | 31,838,491 | 13F-HR | BLAIR WILLIAM & CO/IL |
| Q4 2023 | 2/12/2024 | 1,785 | 29,346,834 | 13F-HR | BLAIR WILLIAM & CO/IL |
| Q3 2023 | 11/9/2023 | 1,791 | 26,075,525 | 13F-HR | BLAIR WILLIAM & CO/IL |
| Q2 2023 | 8/11/2023 | 1,809 | 27,298,221 | 13F-HR | BLAIR WILLIAM & CO/IL |
| Q1 2023 | 5/12/2023 | 1,801 | 25,033,922 | 13F-HR | BLAIR WILLIAM & CO/IL |
| Q4 2022 | 2/10/2023 | 1,814 | 22,998,029 | 13F-HR | BLAIR WILLIAM & CO/IL |
| Q3 2022 | 11/9/2022 | 1,823 | 21,773,212 | 13F-HR | BLAIR WILLIAM & CO/IL |
| Q2 2022 | 8/10/2022 | 1,863 | 22,540,193 | 13F-HR | BLAIR WILLIAM & CO/IL |
| Q1 2022 | 5/13/2022 | 1,910 | 28,529,776 | 13F-HR | BLAIR WILLIAM & CO/IL |
| Q4 2021 | 2/14/2022 | 1,963 | 31,883,204 | 13F-HR | BLAIR WILLIAM & CO/IL |
| Q3 2021 | 11/12/2021 | 1,879 | 29,376,571 | 13F-HR | BLAIR WILLIAM & CO/IL |
| Q2 2021 | 8/12/2021 | 1,888 | 28,857,904 | 13F-HR | BLAIR WILLIAM & CO/IL |
| Q1 2021 | 5/13/2021 | 1,856 | 26,507,771 | 13F-HR | BLAIR WILLIAM & CO/IL |
| Q4 2020 | 2/9/2021 | 1,828 | 27,276,891 | 13F-HR | BLAIR WILLIAM & CO/IL |
| Q3 2020 | 11/6/2020 | 1,720 | 23,576,570 | 13F-HR | BLAIR WILLIAM & CO/IL |
| Q2 2020 | 8/12/2020 | 1,681 | 20,973,250 | 13F-HR | BLAIR WILLIAM & CO/IL |
| Q1 2020 | 5/11/2020 | 1,660 | 15,998,718 | 13F-HR | BLAIR WILLIAM & CO/IL |
| Q4 2019 | 2/13/2020 | 1,728 | 19,456,065 | 13F-HR | BLAIR WILLIAM & CO/IL |
| Q2 2014 | 8/1/2014 | 2,099 | 61,235,793 | 13F-HR | BLAIR WILLIAM & CO/IL |
| Q1 2014 | 5/6/2014 | 2,048 | 60,449,509 | 13F-HR | BLAIR WILLIAM & CO/IL |
| Q4 2013 | 2/11/2014 | 2,015 | 60,502,099 | 13F-HR | BLAIR WILLIAM & CO/IL |
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Money flow by instrument (QoQ, ex-options)
| Type | Value ($000) | Share % | Inflow | Outflow | Net |
|---|---|---|---|---|---|
| Stocks | 34.85 M | 93.6% | 0 | 544.8 K | -544.8 K |
| ETFs | 2.37 M | 6.4% | 235.3 K | 0 | 235.3 K |
| Debt | 28.39 K | 0.1% | 6 | 0 | 6 |
| Other | 2.796 K | 0.0% | 182 | 0 | 182 |
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Fund Snapshot
Q4 2025
Latest filed
2/17/2026
Total value ($000)
37,259,506
Holdings
1867
QoQ value change ($000)
-309,752
(-0.8%)
Value = total reported 13F value ($000), Holdings = number of positions.
13F Value over time
Holdings count over time
Sector allocation (latest, stocks only)
Methodology:
sector allocation is stocks-only;
instrument flow table is ex-options;
options exposure is shown separately.
Details.