§ 13F · FUND PROFILE
BLAIR WILLIAM & CO/IL.
William Blair, quality growth equity
AUM · $36002.5T (13F)Positions · 1824Turnover · 88% · Q4Filed · Feb 17, 2026
CONCENTRATION
27%
Top 10 holdings
NEW BUYS
+126
+$87.9T deployed
EXITS
0
No exits
SECTOR SHIFT
TECHNOLOGY → MEDIA
-1pp · +1pp
3YR HIT RATE
—
Top-5 overlap
§ 01 · TOP HOLDINGS
The book · Q4 2025
FILED FEB 17, 2026
| # | Ticker | Name | Shares | $ value | % port | Δ Q4 |
|---|---|---|---|---|---|---|
| 1 | MSFT | MICROSOFT CORP | 3.57M | $1725.8T | 4.6% | −1% |
| 2 | AAPL | APPLE INC | 5.94M | $1615.0T | 4.3% | −1% |
| 3 | AMZN | AMAZON COM INC | 6.06M | $1398.1T | 3.8% | +1% |
| 4 | NVDA | NVIDIA CORPORATION | 5.48M | $1021.3T | 2.7% | −3% |
| 5 | GOOG | ALPHABET INC | 3.12M | $978.7T | 2.6% | −1% |
| 6 | GOOGL | ALPHABET INC | 2.49M | $778.9T | 2.1% | −1% |
| 7 | JPM | JPMORGAN CHASE & CO. | 2.31M | $744.3T | 2.0% | ±0% |
| 8 | IDXX | IDEXX LABS INC | 1.00M | $677.0T | 1.8% | −3% |
| 9 | V | VISA INC | 1.93M | $676.6T | 1.8% | −2% |
| 10 | SPY | SPDR S&P 500 ETF TR | 858K | $585.0T | 1.6% | ±0% |
§ 02 · SECTOR ALLOCATION
Where the money is
Other38.0% (±0)
Technology17.9% (−1pp)
Financial Services8.1% (±0)
Retail7.5% (±0)
Media7.0% (+1pp)
Health Care6.2% (±0)
§ 03 · THE BLAIR SIGNAL
AC read
BLAIR WILLIAM & CO/IL is a Quality / Compounder fund managing $36002454.6 trillion in assets. The fund runs a massive portfolio of 1,824 positions, broad diversification across holdings, with the top 10 accounting for 27%. Trading activity is aggressive at 88% quarterly turnover, with 126 new positions and 0 exits last quarter. Top sector allocations: Other (38%), Technology (18%), Financial Services (8%).
Read the full dossier →§ 04 · FILING HISTORY
Q-by-Q deltas
1 FILINGS
Q4 2025
Busy quarter
+126 buys · −0 exits · 1561 changed
Q3 2025
Steady book
+0 buys · −0 exits · 0 changed
Q2 2025
Steady book
+0 buys · −0 exits · 0 changed
Q1 2025
Steady book
+0 buys · −0 exits · 0 changed