13F Insight
DOSSIER · 13F-HR · Q1 2026

BLAIR WILLIAM & CO/IL

$34.9B in tracked AUM across 1,922 positions as of Q1 2026.

BW
CIK 0000902367 · last filed Mar 31, 2026
Total AUM
$34.9B
as of Q1 2026
Holdings
1,922
—
positions
Whale Score
56
56
tracked
Activity
—
no data
changes this Q
AI Analysis · Q1 2026

Portfolio Overview

Blair William & Co. manages a substantial, diversified equity portfolio valued at approximately $37.57 billion as of September 30, 2025. The firm experienced a positive quarter, growing assets under management by 4.4% from the previous quarter's $36.00 billion. The portfolio is highly diversified, encompassing 1,844 individual holdings. Despite the large number of positions, the firm employs a core-satellite approach where a significant portion of the capital is concentra...

Key Holdings

The portfolio is anchored by mega-cap technology leaders, which dominate the top rankings. Microsoft (MSFT) is the largest holding at $1.87 billion (4.97% of the portfolio), followed closely by Apple (AAPL) at $1.53 billion (4.06%) and Amazon (AMZN) at $1.32 billion (3.51%). These three companies alone constitute over 12.5% of the total assets, indicating a strong conviction in the dominant U.S. technology franchises.

Analysis generated by 13F Insight from SEC Form 13F filing data · Q1 2026. Methodology

Quarter at a glance — Q1 2026

Position-change comparison pending.

No quarter-over-quarter changes available.

Top 10 holdings

By portfolio weight as of Q1 2026.

#HoldingValueSharesWeight
01
AAPL
APPLE INC
$1.5B5.9M4.3%02
MSFT
MICROSOFT CORP
$1.3B3.5M3.7%03
AMZN
AMAZON COM INC
$1.3B6.1M3.6%04
NVDA
NVIDIA CORPORATION
$947M5.4M2.7%05
GOOG
ALPHABET INC
$871M3.0M2.5%06
GOOGL
ALPHABET INC
$701M2.4M2.0%07
JPM
JPMORGAN CHASE & CO
$679M2.3M1.9%08
GEV
GE VERNOVA INC
$580M665K1.7%09
V
VISA INC
$558M1.8M1.6%10
SPY
STATE STR SPDR S&P 500 ETF T
$550M845K1.6%

Filing history

2026Q1Mar 31
$34.9B▼ 6.3%
1,922 positionsView →2025Q4Dec 31
$37.3B▼ 0.8%
1,920 positionsView →2025Q3Sep 30
$37.6B▲ 4.4%
1,844 positionsView →2025Q2Jun 30
$36.0B▲ 8.6%
1,824 positionsLocked2025Q1Mar 31
$33.2B▼ 3.6%
1,801 positionsLocked2024Q4Dec 31
$34.4B▲ 1.0%
1,816 positionsLocked2024Q3Sep 30
$34.1B▲ 5.0%
1,821 positionsLocked2024Q2Jun 30
$32.4B▲ 1.8%
1,822 positionsLocked2024Q1Mar 31
$31.8B▲ 8.5%
1,787 positionsLocked2023Q4Dec 31
$29.3B▲ 12.5%
1,785 positionsLocked2023Q3Sep 30
$26.1B▼ 4.5%
1,791 positionsLocked2023Q2Jun 30
$27.3B▲ 9.0%
1,809 positionsLocked
Showing 12 of 100