DOSSIER · 13F Holders · Q1 2026
ASRT

ASSERTIO HLDGS INC

65 institutions still hold ASSERTIO HLDGS INC as of Q1 2026. Tracked across SEC 13F-HR filings, with insider and 13D/G activity surfaced alongside.

CUSIP 04546C304·65 13F holders·last filed Mar 31, 2026
Market cap
13F value held
$41M
visible holders
Holders
65
filers reporting
Concentration
31.81%
Nantahala Capital Management, LLC #1
top holder share
AI Holders Summary · Q1 2026

Assertio Holdings (ASRT) shows a more developed base than most micro-caps — 61 holders and about $43.7M in combined 13F value as of Q1 2026. Nantahala Capital leads decisively at roughly $13.2M (30% of the book), well ahead of index holders Vanguard ($5.1M) and Renaissance Technologies ($4.4M). Nantahala's outsized stake is the conviction signal in an otherwise index-heavy register.

The standout is Nantahala Capital, a fundamental small-cap manager, which holds roughly $13.2 million — about 30% of the entire disclosed value and far ahead of the next names. Below it the register turns passive: Vanguard ($5.1M) and Renaissance Technologies ($4.4M) are index- and quant-driven rather than conviction positions.

That structure is the story for ASRT: one active manager with a concentrated bet, sitting atop a base that is otherwise largely passive. For readers, Nantahala's position is the one to watch — it represents the genuine fundamental interest in the name, where index flows make up much of the remainder.

Top holders

Sorted by position value. Source: SEC EDGAR 13F-HR filings.

#HolderValueShares% port.Quarter
01
Nantahala Capital Management, LLC
CIK 0001472322
$13M692K0.49%Q1 2026
02
VANGUARD CAPITAL MANAGEMENT LLC
CIK 0002100119· Index
$5M269K0.00%Q1 2026
03
RENAISSANCE TECHNOLOGIES LLC
CIK 0001037389
$4M229K0.01%Q1 2026
04
SUSQUEHANNA INTERNATIONAL GROUP, LLP
CIK 0001446194· Market maker
$3M182K0.00%Q1 2026
05
EDGEWOOD MANAGEMENT LLC
CIK 0000860561
$2M108K0.01%Q1 2026
06
BlackRock, Inc.
CIK 0002012383
$2M90K0.00%Q1 2026
07
JANE STREET GROUP, LLC
CIK 0001595888· Market maker
$2M79K0.00%Q1 2026
08
GEODE CAPITAL MANAGEMENT, LLC
CIK 0001214717· Index
$1M76K0.00%Q1 2026
09
Walleye Capital LLC
CIK 0001758720
$1M66K0.01%Q1 2026
10
SEI INVESTMENTS CO
CIK 0000350894
$1M55K0.00%Q1 2026
11
Huntleigh Advisors, Inc.
CIK 0001367653
$1M53K0.17%Q1 2026
12
Informed Momentum Co LLC
CIK 0001510989
$860K45K0.10%Q1 2026
13
CM Management, LLC
CIK 0001841857
$667K35K0.56%Q1 2026
14
VANGUARD FIDUCIARY TRUST CO
CIK 0000933478· Index
$655K34K0.00%Q1 2026
15
TWO SIGMA INVESTMENTS, LP
CIK 0001179392
$640K34K0.00%Q1 2026
16
STATE STREET CORP
CIK 0000093751
$529K28K0.00%Q1 2026
17
CITADEL ADVISORS LLC
CIK 0001423053
$512K56K0.00%Q4 2025
18
CORSAIR CAPITAL MANAGEMENT, L.P.
CIK 0001276470
$487K26K0.07%Q1 2026
19
TSP Capital Management Group, LLC
CIK 0001317208
$478K25K0.12%Q1 2026
20
BANK OF AMERICA CORP /DE/
CIK 0000070858
$477K25K0.00%Q1 2026
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Insiders at ASSERTIO HLDGS INC
Stark David MatthewMason Heather LReisenauer Mark LSchwichtenberg PaulEmany Sravan KumarKirk SigurdSchlessinger SamMckee William