iShares Biotechnology ETF (IBB), issued by BlackRock, reported 256 long positions and $8.1B in net assets in its Mar 2026 N-PORT filing. The ten largest positions account for 54.71% of net assets.
Reporting period: 31 Mar 2026 · 8 filings on file · N-PORT is filed monthly and published quarterly, roughly 60 days in arrears
Net assets
$8.1B
As of Mar 2026
Positions
256
Long positions in the filing
Top 10 weight
54.71%
Top 25: 75.37%
Effective holdings
24
Concentrated
Cash
0.00%
Share of net assets
Securities on loan
10.1778%
204 positions on loan
Sector exposure
5 sectors · Mar 2026
Health Care76.60%
Unclassified11.91%
Funds8.96%
Technology2.53%
Materials0.01%
Ten largest holdings
Top 10 of 258 positions · Mar 2026
Ten largest holdings reported by IBB as of 31 Mar 2026
#
Security
CUSIP
Value
% of net assets
1
BCF INSTITUTIONAL-SL AGNCY
066922519
$784.8M
9.66%
2
GILEAD SCIENCES INC
375558103
$629.4M
7.75%
3
AMGEN INC
031162100
$609.8M
7.51%
4
VERTEX PHARMACEUTICALS INC
92532F100
$604.6M
7.44%
5
REGENERON PHARMACEUTICALS
75886F107
$585.8M
7.21%
6
ALNYLAM PHARMACEUTICALS INC
02043Q107
$324.1M
3.99%
7
INSMED INC
457669307
$259.7M
3.20%
8
ARGENX SE - ADR
04016X101
$249.7M
3.07%
9
BIOGEN INC
09062X103
$200.0M
2.46%
10
NATERA INC
632307104
$196.1M
2.41%
Full holdings, position changes between periods, fund overlap, cross-fund crowding and securities lending detail for IBB are in the ETF X-Ray dashboard.