Rock Springs Capital

**Signal Note: Rock Springs Capital initiates $113.3M LLY position** Rock Springs' entry into Lilly suggests conviction in near-term catalysts, likely tied to GLP-1 competitive dynamics (tirzepatide in obesity/diabetes) or advancement in their neuroscience pipeline (donanemab for Alzheimer's). The $113.3M position size indicates this is a meaningful conviction play for the concentrated fund, warranting monitoring of upcoming clinical data readouts, FDA decisions, or quarterly earnings revisions that could validate or challenge the thesis.

# Signal Note: Rock Springs Capital Initiates $106.4M RVMD Position Rock Springs' $106.4M entry into Revolution Medicines signals conviction in the company's RLY471 program for NF1, a high-unmet-need indication with limited approved therapeutics. The position timing likely reflects confidence ahead of near-term clinical catalysts, potentially including Phase 2 efficacy data or regulatory interactions that could de-risk the NF1 pathway. As a concentrated long/short specialist, Rock Springs' initiation suggests attractive risk-reward relative to peers in the kinase inhibitor space.

# Signal Note: Rock Springs Capital Initiates $86.8M ARGX Position Rock Springs' significant entry suggests conviction in argenx's near-term catalysts, likely centered on efgartigimod's commercial ramp in myasthenia gravis (MG) and anticipated label expansions (IgG4-related disease decision expected late 2024). The position size—103k shares representing ~0.8% of shares outstanding—indicates meaningful conviction despite ARGX's $11B+ market cap, suggesting the fund sees meaningful upside from pipeline de-risking or MG market penetration beyond current Street consensus.

**Signal Note: Rock Springs Capital initiates $84.5M position in TVTX** Rock Springs' concentrated healthcare fund entered a material 2.2M-share position in Travere, likely betting on upcoming regulatory/commercial inflection points for IgA nephropathy franchises (fostamatinib marketed; next-gen pipeline assets in clinical stage). The $84.5M position size suggests conviction on either near-term label expansions, Phase 3 readouts, or valuation disconnect relative to peak sales potential in a ~$1.5B+ addressable market.

# Signal Note: Rock Springs Capital Initiates $81.3M Position in Madrigal Pharmaceuticals Rock Springs' substantial entry into MDGL signals conviction in resmetirom (Rezdiffra), the GLP-1-independent NASH therapeutic approved by FDA in March 2024. The $81.3M position (~4.5% of market cap) suggests confidence in near-term revenue ramp and/or upcoming clinical catalysts, potentially including NASH combination trial data or label expansion into metabolic dysfunction-associated fatty liver disease (MAFLD). Timing coincides with early commercial uptake phase and heightened competition in the NASH space from Eli Lilly and Viking Therapeutics.

# Signal Note: Rock Springs Capital Initiates $74.4M RYTM Position Rock Springs' meaningful entry into Rhythm suggests conviction in upcoming catalysts for setmelanotide (IMCIVREE), likely tied to label expansions or commercial execution in rare genetic obesity indications. The healthcare specialist's concentrated strategy typically requires high-conviction theses with defined near-term de-risking events—possible near-term readouts, reimbursement developments, or guidance revisions could be the catalyst. At current positioning, the fund is signaling confidence in RYTM's ability to unlock value in a narrowly competed rare disease space.

# Signal Note: Rock Springs Capital Initiates $61.1M Position in EXAS Healthcare specialist Rock Springs' new $61.1M stake in Exact Sciences signals confidence in the company's multi-cancer early detection platform, particularly Galleri, which has shown clinical utility across multiple cancer types and faces a potential Medicare coverage decision in 2025. The concentrated long position suggests conviction in either near-term reimbursement catalysts or clinical validation data that could drive adoption in screening populations.

# Signal Note: Rock Springs Capital Initiates $60.2M Position in MIRM Rock Springs' substantial new position in Mirum suggests conviction in the company's late-stage pipeline, likely centered on **maralixibat for progressive familial intrahepatic cholestasis (PFIC)**, which has shown clinical efficacy in reducing pruritus and bile acid levels in pediatric patients. The timing aligns with anticipated regulatory catalysts, including potential FDA feedback or label expansion discussions, though near-term catalysts should be monitored against cash runway and partnership developments. This concentrated bet reflects a high-conviction thesis on a rare disease asset with limited competitive alternatives.

# Signal Note: Rock Springs Capital Initiates $55.6M INSM Position Rock Springs' $55.6M entry into Insmed signals conviction in the company's pulmonary portfolio, likely driven by momentum in ARIKAYCE (liposomal amikacin) for nontuberculous mycobacteria (NTM) lung infections, which has shown steady uptake since 2018 launch and faces limited competition. The timing suggests confidence ahead of potential label expansions, pipeline readouts (particularly TORUS trials), or positive feedback on reimbursement/market access. Given Rock Springs' healthcare specialization and concentrated approach, this stakes a material bet on execution of Insmed's commercial strategy and clinical pipeline rather than near-term M&A speculation.

# Signal Note: Rock Springs Capital Initiates $52M Position in Structure Therapeutics Rock Springs' entry into GPCR represents conviction in Structure's lead program GSBR-1290 for AATD (alpha-1 antitrypsin deficiency), a rare lung disease with limited approved options and potential for rapid clinical progression. The $52M position size (748k shares) signals confidence ahead of near-term catalysts, likely Phase 2b data or regulatory feedback on the oral GPCR modulator approach, which offers differentiation versus inhaled/IV AAT replacement therapies on convenience and bioavailability metrics. This follows Structure's recent $75M financing and suggests the specialist fund sees undervalued risk-reward at current valuations (~$70/share).

Rock Springs' $46.4M initiation of 82,000 ISRG shares signals conviction in surgical robotics demand despite recent valuation compression and competitive pressures from Stryker/J&J. The position timing suggests confidence in da Vinci's installed base expansion and procedure volume recovery post-inflation, though near-term margin expansion remains dependent on operating leverage as the installed base matures.

# Signal Note: Rock Springs Capital Initiates $43.4M ASND Position Rock Springs' entry into ASND suggests conviction in Ascendis' lonapegsomatropin franchise, likely ahead of potential label expansions or pediatric growth hormone deficiency market share gains. The $43.4M stake (substantial for a concentrated fund) indicates confidence in clinical/commercial execution, possibly tied to upcoming PDUFA dates, international approvals, or endocrinology market tailwinds. Key catalysts to monitor: FDA decisions on additional indications and Q4 earnings guidance on patient uptake and payer coverage trajectory.

# Signal Note: Rock Springs Capital Initiates $38.7M Position in KYMR Rock Springs' entry suggests conviction in Kymera's pipeline execution, likely centered on near-term catalysts from its PROTAC degrader programs targeting high-value oncology indications. The $38.7M position size (496K shares ~7-8% of float) indicates meaningful conviction for a concentrated healthcare hedge fund, signaling potential visibility into upcoming trial data or partnership developments that could de-risk the platform's clinical/commercial prospects.

# Signal Note: Rock Springs Capital BSX Position Rock Springs Capital's $38M initiation in Boston Scientific suggests conviction in near-term catalysts within the company's interventional portfolio, likely tied to upcoming clinical readouts or FDA decisions in structural heart or endovascular markets where BSX maintains leading positions. The concentrated builder's entry into a $180B+ market cap compounder may indicate positioning ahead of Q4 earnings or upcoming regulatory milestones, though specific catalyst timing is not disclosed in the filing.

# Signal Note: Rock Springs Capital Initiates $37.5M Penumbra Position Rock Springs' entry into PEN suggests conviction in the company's neurointerventional device portfolio, likely driven by upcoming clinical data or reimbursement milestones for its ischemic stroke and hemorrhagic stroke platforms. As a healthcare specialist with a concentrated mandate, the position size (120.5K shares) represents meaningful conviction and warrants monitoring for Q3/Q4 2024 catalyst events, including potential FDA decisions or clinical readout announcements that could drive procedural adoption in the interventional radiology market.