Ionis Pharmaceuticals Inc.

IONS

Held by 3 specialist biotech funds

High Convergence

Share on X

Fund Holdings

3 fund convergence

Baker Bros. Advisors Deerfield Management Eventide Asset Management

Position Trend

Feb 13, 2026

$45.5M

1 fund

Feb 17, 2026

$393.7M

2 funds

+765% total institutional value over 2 quarters

Catalysts

Phase 2Jun 26, 2025sapablursenPhlebotomy Dependent Polycythemia Vera

Phase 3Aug 22, 2025zilganersenAlexander Disease

Phase 3

Position Details

Baker Bros. AdvisorsNEWFeb 17, 2026

Shares: 1,791,841Value: $141.8M

## Signal Note: Baker Bros. Initiates Major Position in Ionis Pharmaceuticals (IONS) Baker Bros. building a ~$142M position in IONS is a high-conviction signal given the fund's concentrated, deep-diligence approach to biotech — they typically initiate at this scale only when they see a clear catalyst path. The most likely thesis centers on Ionis's pipeline inflection points, including olezarsen (cardiovascular/familial chylomicronemia syndrome) with a PDUFA date in Q4 2025, donidalorsen for hereditary angioedema (under FDA review), and the broader validation of their antisense platform following the Eplontersen (TTR) commercial ramp. The timing suggests Baker is positioning ahead of multiple binary regulatory catalysts and potential proof-of-concept that Ionis can transition from a royalty/partnership model to a self

Deerfield ManagementNEW

Know which insider moves are real

See who's buying with their own money vs. routine exercises
AI explains why each move matters right now

Start 7-Day Free Trial — $29/mo

Insider Signals

No insider signals tracked.

Also Held by These Funds

ARWR3 funds IRON3 funds CELC3 funds EWTX3 funds IDYA3 funds KYMR3 funds RVMD3 funds SION

Research Links

Yahoo Finance →SEC EDGAR →ClinicalTrials.gov →

Track specialist biotech funds, insider signals, and AI analysis

Start 7-Day Free Trial

Or get the free weekly brief:

AI Signal

## Signal Note: Baker Bros.

AI analyst context — unlock full analysis

Transthyretin-Mediated Amyloid Cardiomyopathy (ATTR CM)

Phase 3Jun 30, 2026ION363Amyotrophic Lateral Sclerosis

Phase 3Dec 31, 2026DonidalorsenHereditary Angioedema

Phase 2Feb 28, 2027ION717Prion Disease

Phase 3Mar 31, 2027OlezarsenSevere Hypertriglyceridemia

Phase 3Jun 30, 2027OlezarsenFamilial Chylomicronemia Syndrome

Phase 3Aug 31, 2027ION582Angelman Syndrome

Phase 2Sep 30, 2027ION440Methyl CpG Binding Protein 2 (MECP2) Duplication Syndrome

Phase 3Feb 29, 2028OlezarsenFamilial Chylomicronemia Syndrome

Phase 2Mar 31, 2029ION582Angelman Syndrome

Phase 3Jun 30, 2029DonidalorsenHereditary Angioedema (HAE)

Phase 3Aug 31, 2029EplontersenHereditary Transthyretin-Mediated Amyloid Polyneuropathy

Phase 3Aug 31, 2029EplontersenTransthyretin-Mediated Amyloid Cardiomyopathy (ATTR CM)

Shares: 61,979,669Value: $251.9M

**Signal Note: Deerfield initiates $252M position in IONS** Deerfield's sizable entry into Ionis suggests conviction in the company's antisense pipeline, likely driven by near-term catalysts including potential FDA decisions on lead programs (spinraza generics risk, but newer candidates like AKCEA-APOC3 in cardiovascular disease and IONIS-FB-LRx in Factor B-mediated diseases offer growth vectors). The timing aligns with Ionis's shift toward partnered development and royalty-based revenue model, which may appeal to Deerfield's multi-strategy thesis on capital efficiency and reduced execution risk.

+ 1more — see how much conviction went in

See the Full Story