Prothena (PRTA)
Market Price (5/7/2026): $11.175 | Market Cap: $601.6 MilSector: Health Care | Industry: Biotechnology
Prothena (PRTA)
Market Price (5/7/2026): $11.175Market Cap: $601.6 MilSector: Health CareIndustry: Biotechnology
Investment Highlights Why It Matters Detailed financial logic regarding cash flow yields vs trend-riding momentum.
Cash is significant % of market capNet D/ENet Debt/Equity. Debt net of cash. Negative indicates net cash. Equity is taken as the Market Capitalization is -50% Megatrend and thematic driversMegatrends include Precision Medicine, and Aging Population & Chronic Disease. Themes include Targeted Therapies, Biopharmaceutical R&D, Show more. | Trading close to highsDist 52W High is -2.9% Weak multi-year price returns2Y Excs Rtn is -95%, 3Y Excs Rtn is -156% Meaningful short interestShort Interest % of Basic SharesShort Interest % of Basic Shares = (Short Interest Quantity) / (Basic Shares Outstanding). A high fraction of short interest can indicate potential risk of a short squeeze. is 13% | Not profitable at operating income levelOp Inc LTMOperating Income, Last Twelve Months is -185 Mil, Op Mgn LTMOperating Margin = Operating Income / Revenue Reflects profitability before taxes and before impact of capital structure (interest payments). is -1906% Weak revenue growthRev Chg LTMRevenue Change % Last Twelve Months (LTM) is -93%, Rev Chg QQuarterly Revenue Change % is -99% Significant share based compensationSBC/Rev LTMShare Based Compensation / Revenue (Sales), Last Twelve Months (LTM) is 389% Not cash flow generativeCFO/Rev LTMCash Flow from Operations / Revenue (Sales), Last Twelve Months (LTM) is -1689%, FCF/Rev LTMFree Cash Flow / Revenue (Sales), Last Twelve Months (LTM) is -1691% Yield minus risk free rate is negativeERPEquity Risk Premium (ERP) = Total Yield - Risk Free Rate, Reflects the premium above risk free assets offered by the investment. is -44% Significant short interestShort Interest Days-to-CoverDTC = (Short Interest Share Quantity) / (Average Daily Trading Volume). Reflects how many days it would take to cover (close out) the short interest based on average volumes. High DTC can signify an increased risk of a short squeeze. is 15.33 Key risksPRTA key risks include [1] a heavy dependence on its narrowed pipeline of high-risk neurodegenerative candidates following the Phase 3 failure of its former lead candidate, Show more. |
| Cash is significant % of market capNet D/ENet Debt/Equity. Debt net of cash. Negative indicates net cash. Equity is taken as the Market Capitalization is -50% |
| Megatrend and thematic driversMegatrends include Precision Medicine, and Aging Population & Chronic Disease. Themes include Targeted Therapies, Biopharmaceutical R&D, Show more. |
| Trading close to highsDist 52W High is -2.9% |
| Weak multi-year price returns2Y Excs Rtn is -95%, 3Y Excs Rtn is -156% |
| Meaningful short interestShort Interest % of Basic SharesShort Interest % of Basic Shares = (Short Interest Quantity) / (Basic Shares Outstanding). A high fraction of short interest can indicate potential risk of a short squeeze. is 13% |
| Not profitable at operating income levelOp Inc LTMOperating Income, Last Twelve Months is -185 Mil, Op Mgn LTMOperating Margin = Operating Income / Revenue Reflects profitability before taxes and before impact of capital structure (interest payments). is -1906% |
| Weak revenue growthRev Chg LTMRevenue Change % Last Twelve Months (LTM) is -93%, Rev Chg QQuarterly Revenue Change % is -99% |
| Significant share based compensationSBC/Rev LTMShare Based Compensation / Revenue (Sales), Last Twelve Months (LTM) is 389% |
| Not cash flow generativeCFO/Rev LTMCash Flow from Operations / Revenue (Sales), Last Twelve Months (LTM) is -1689%, FCF/Rev LTMFree Cash Flow / Revenue (Sales), Last Twelve Months (LTM) is -1691% |
| Yield minus risk free rate is negativeERPEquity Risk Premium (ERP) = Total Yield - Risk Free Rate, Reflects the premium above risk free assets offered by the investment. is -44% |
| Significant short interestShort Interest Days-to-CoverDTC = (Short Interest Share Quantity) / (Average Daily Trading Volume). Reflects how many days it would take to cover (close out) the short interest based on average volumes. High DTC can signify an increased risk of a short squeeze. is 15.33 |
| Key risksPRTA key risks include [1] a heavy dependence on its narrowed pipeline of high-risk neurodegenerative candidates following the Phase 3 failure of its former lead candidate, Show more. |
Qualitative Assessment
AI Analysis | Feedback
Prothena (PRTA) stock has gained about 25% since 1/31/2026 because of the following key factors:
1. Positive Clinical Development and Milestones for Key Programs.
Prothena experienced a notable gain due to advancements and positive data from its partnered clinical programs. On March 9, 2026, the company earned a $50 million clinical milestone payment from Novo Nordisk following the achievement of a prespecified enrollment target in the ongoing Phase 3 CLEOPATTRA clinical trial for coramitug (formerly PRX004) in ATTR amyloidosis with cardiomyopathy. This payment contributes to a total of $150 million earned to date out of $1.2 billion in total eligible milestone payments from Novo Nordisk. Additionally, on April 27, 2026, Novo Nordisk obtained Fast Track Designation from the U.S. FDA for coramitug, which may expedite its review process. Further positive sentiment was generated on March 21, 2026, when partners presented clinical updates for prasinezumab in Parkinson's disease and BMS-986446 in Alzheimer's disease, with prasinezumab data suggesting an estimated two years of "time saved" in disease progression.
2. Share Repurchase Authorization.
On February 27, 2026, Prothena's Board of Directors authorized a share repurchase plan of up to $100 million of its outstanding ordinary shares, signaling management's confidence in the company's value and potentially enhancing shareholder value by reducing the share count. This plan is set to expire on December 31, 2026.
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1. Positive Clinical Development and Milestones for Key Programs.
Prothena experienced a notable gain due to advancements and positive data from its partnered clinical programs. On March 9, 2026, the company earned a $50 million clinical milestone payment from Novo Nordisk following the achievement of a prespecified enrollment target in the ongoing Phase 3 CLEOPATTRA clinical trial for coramitug (formerly PRX004) in ATTR amyloidosis with cardiomyopathy. This payment contributes to a total of $150 million earned to date out of $1.2 billion in total eligible milestone payments from Novo Nordisk. Additionally, on April 27, 2026, Novo Nordisk obtained Fast Track Designation from the U.S. FDA for coramitug, which may expedite its review process. Further positive sentiment was generated on March 21, 2026, when partners presented clinical updates for prasinezumab in Parkinson's disease and BMS-986446 in Alzheimer's disease, with prasinezumab data suggesting an estimated two years of "time saved" in disease progression.
2. Share Repurchase Authorization.
On February 27, 2026, Prothena's Board of Directors authorized a share repurchase plan of up to $100 million of its outstanding ordinary shares, signaling management's confidence in the company's value and potentially enhancing shareholder value by reducing the share count. This plan is set to expire on December 31, 2026.
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Stock Movement Drivers
Fundamental Drivers
The 26.9% change in PRTA stock from 1/31/2026 to 5/6/2026 was primarily driven by a 54.5% change in the company's P/S Multiple.| (LTM values as of) | 1312026 | 5062026 | Change |
|---|---|---|---|
| Stock Price ($) | 8.81 | 11.18 | 26.9% |
| Change Contribution By: | |||
| Total Revenues ($ Mil) | 12 | 10 | -17.8% |
| P/S Multiple | 40.2 | 62.1 | 54.5% |
| Shares Outstanding (Mil) | 54 | 54 | 0.0% |
| Cumulative Contribution | 26.9% |
Market Drivers
1/31/2026 to 5/6/2026| Return | Correlation | |
|---|---|---|
| PRTA | 26.9% | |
| Market (SPY) | 3.6% | 48.7% |
| Sector (XLV) | -5.6% | 52.8% |
Fundamental Drivers
The 4.0% change in PRTA stock from 10/31/2025 to 5/6/2026 was primarily driven by a 11.1% change in the company's P/S Multiple.| (LTM values as of) | 10312025 | 5062026 | Change |
|---|---|---|---|
| Stock Price ($) | 10.75 | 11.18 | 4.0% |
| Change Contribution By: | |||
| Total Revenues ($ Mil) | 10 | 10 | -6.4% |
| P/S Multiple | 56.0 | 62.1 | 11.1% |
| Shares Outstanding (Mil) | 54 | 54 | 0.0% |
| Cumulative Contribution | 4.0% |
Market Drivers
10/31/2025 to 5/6/2026| Return | Correlation | |
|---|---|---|
| PRTA | 4.0% | |
| Market (SPY) | 5.5% | 36.3% |
| Sector (XLV) | 1.6% | 39.9% |
Fundamental Drivers
The 21.5% change in PRTA stock from 4/30/2025 to 5/6/2026 was primarily driven by a 1596.5% change in the company's P/S Multiple.| (LTM values as of) | 4302025 | 5062026 | Change |
|---|---|---|---|
| Stock Price ($) | 9.20 | 11.18 | 21.5% |
| Change Contribution By: | |||
| Total Revenues ($ Mil) | 135 | 10 | -92.8% |
| P/S Multiple | 3.7 | 62.1 | 1596.5% |
| Shares Outstanding (Mil) | 54 | 54 | 0.0% |
| Cumulative Contribution | 21.5% |
Market Drivers
4/30/2025 to 5/6/2026| Return | Correlation | |
|---|---|---|
| PRTA | 21.5% | |
| Market (SPY) | 30.4% | 20.0% |
| Sector (XLV) | 5.4% | 25.5% |
Fundamental Drivers
The -78.8% change in PRTA stock from 4/30/2023 to 5/6/2026 was primarily driven by a -82.0% change in the company's Total Revenues ($ Mil).| (LTM values as of) | 4302023 | 5062026 | Change |
|---|---|---|---|
| Stock Price ($) | 52.62 | 11.18 | -78.8% |
| Change Contribution By: | |||
| Total Revenues ($ Mil) | 54 | 10 | -82.0% |
| P/S Multiple | 47.8 | 62.1 | 30.0% |
| Shares Outstanding (Mil) | 49 | 54 | -9.0% |
| Cumulative Contribution | -78.8% |
Market Drivers
4/30/2023 to 5/6/2026| Return | Correlation | |
|---|---|---|
| PRTA | -78.8% | |
| Market (SPY) | 78.7% | 23.2% |
| Sector (XLV) | 14.5% | 24.3% |
Price Returns Compared
| 2021 | 2022 | 2023 | 2024 | 2025 | 2026 | Total [1] | |
|---|---|---|---|---|---|---|---|
| Returns | |||||||
| PRTA Return | 311% | 22% | -40% | -62% | -31% | 17% | -7% |
| Peers Return | 0% | 15% | 9% | -4% | 46% | -3% | 72% |
| S&P 500 Return | 27% | -19% | 24% | 23% | 16% | 6% | 93% |
Monthly Win Rates [3] | |||||||
| PRTA Win Rate | 58% | 50% | 42% | 25% | 58% | 60% | |
| Peers Win Rate | 47% | 55% | 47% | 38% | 58% | 40% | |
| S&P 500 Win Rate | 75% | 42% | 67% | 75% | 67% | 60% | |
Max Drawdowns [4] | |||||||
| PRTA Max Drawdown | -8% | -54% | -46% | -67% | -67% | -13% | |
| Peers Max Drawdown | -24% | -24% | -25% | -26% | -24% | -14% | |
| S&P 500 Max Drawdown | -1% | -25% | -1% | -2% | -15% | -7% | |
[1] Cumulative total returns since the beginning of 2021
[2] Peers: BIIB, LLY, ALNY, IONS, DNLI. See PRTA Returns vs. Peers.
[3] Win Rate = % of calendar months in which monthly returns were positive
[4] Max drawdown represents maximum peak-to-trough decline within a year
[5] 2026 data is for the year up to 5/6/2026 (YTD)
How Low Can It Go
| Event | PRTA | S&P 500 |
|---|---|---|
| 2023 SVB Regional Banking Crisis | ||
| % Loss | -13.0% | -6.7% |
| % Gain to Breakeven | 14.9% | 7.1% |
| Time to Breakeven | 30 days | 31 days |
| 2022 Inflation Shock & Fed Tightening | ||
| % Loss | -53.8% | -24.5% |
| % Gain to Breakeven | 116.5% | 32.4% |
| Time to Breakeven | 107 days | 427 days |
| 2020 COVID-19 Crash | ||
| % Loss | -37.1% | -33.7% |
| % Gain to Breakeven | 58.9% | 50.9% |
| Time to Breakeven | 33 days | 140 days |
| Q4 2018 Fed Policy Error / Growth Scare | ||
| % Loss | -36.5% | -19.2% |
| % Gain to Breakeven | 57.4% | 23.7% |
| Time to Breakeven | 67 days | 105 days |
| 2016-2017 Trump Reflation Bond Selloff | ||
| % Loss | -33.6% | -3.7% |
| % Gain to Breakeven | 50.7% | 3.9% |
| Time to Breakeven | 8 days | 6 days |
| 2015-2016 China Devaluation / Global Growth Scare | ||
| % Loss | -51.5% | -12.2% |
| % Gain to Breakeven | 106.0% | 13.9% |
| Time to Breakeven | 223 days | 62 days |
In The Past
Prothena's stock fell -8.3% during the 2024 Yen Carry Trade Unwind. Such a loss loss requires a 9.1% gain to breakeven.
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Asset Allocation
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| Event | PRTA | S&P 500 |
|---|---|---|
| 2022 Inflation Shock & Fed Tightening | ||
| % Loss | -53.8% | -24.5% |
| % Gain to Breakeven | 116.5% | 32.4% |
| Time to Breakeven | 107 days | 427 days |
| 2020 COVID-19 Crash | ||
| % Loss | -37.1% | -33.7% |
| % Gain to Breakeven | 58.9% | 50.9% |
| Time to Breakeven | 33 days | 140 days |
| Q4 2018 Fed Policy Error / Growth Scare | ||
| % Loss | -36.5% | -19.2% |
| % Gain to Breakeven | 57.4% | 23.7% |
| Time to Breakeven | 67 days | 105 days |
| 2016-2017 Trump Reflation Bond Selloff | ||
| % Loss | -33.6% | -3.7% |
| % Gain to Breakeven | 50.7% | 3.9% |
| Time to Breakeven | 8 days | 6 days |
| 2015-2016 China Devaluation / Global Growth Scare | ||
| % Loss | -51.5% | -12.2% |
| % Gain to Breakeven | 106.0% | 13.9% |
| Time to Breakeven | 223 days | 62 days |
| 2014-2016 Oil Price Collapse | ||
| % Loss | -23.7% | -6.8% |
| % Gain to Breakeven | 31.0% | 7.3% |
| Time to Breakeven | 28 days | 15 days |
In The Past
Prothena's stock fell -8.3% during the 2024 Yen Carry Trade Unwind. Such a loss loss requires a 9.1% gain to breakeven.
Preserve Wealth
Limiting losses and compounding gains is essential to preserving wealth.
Asset Allocation
Actively managed asset allocation strategies protect wealth. Learn more.
About Prothena (PRTA)
Prothena Corporation plc, a late-stage clinical company, focuses on discovery and development of novel therapies for life-threatening diseases in the United States. The company is involved in developing Birtamimab, an investigational humanized antibody that is in Phase III clinical trial for the treatment of AL amyloidosis; Prasinezumab, a humanized monoclonal antibody, which is in Phase IIb clinical trial for the treatment of Parkinson's disease; PRX004 that completed Phase I clinical trial for the treatment of Transthyretin amyloidosis; and PRX005, which is in Phase I clinical trial for the treatment of Alzheimer's disease. Its discovery and preclinical programs include PRX012 for the treatment of Alzheimer's disease; and dual Aß-Tau vaccine for the treatment and prevention of Alzheimer's disease. Prothena Corporation plc has a license, development, and commercialization agreement with F. Hoffmann-La Roche Ltd. and Hoffmann-La Roche Inc. to develop and commercialize antibodies that target alpha-synuclein; and a collaboration agreement with Bristol-Myers Squibb to develop antibodies. The company was founded in 2012 and is based in Dublin, Ireland.
AI Analysis | Feedback
Here are 1-3 brief analogies to describe Prothena:
- Like a clinical-stage Biogen or Eli Lilly, focused on breakthrough treatments for Alzheimer's, Parkinson's, and rare protein diseases.
- An early-stage Genentech or Amgen, concentrated purely on developing novel therapies for challenging neurological and rare diseases.
AI Analysis | Feedback
- Birtamimab: An investigational humanized antibody in Phase III clinical trial for the treatment of AL amyloidosis.
- Prasinezumab: A humanized monoclonal antibody in Phase IIb clinical trial for the treatment of Parkinson's disease.
- PRX004: An investigational therapy that completed Phase I clinical trial for the treatment of Transthyretin amyloidosis.
- PRX005: An investigational therapy in Phase I clinical trial for the treatment of Alzheimer's disease.
- PRX012: A discovery and preclinical program targeting Alzheimer's disease.
- Dual Aß-Tau vaccine: A discovery and preclinical program for the treatment and prevention of Alzheimer's disease.
AI Analysis | Feedback
Prothena (PRTA) primarily operates by discovering and developing novel therapies and then entering into licensing, development, and commercialization agreements with larger pharmaceutical companies. Therefore, its major customers are other companies, not individuals.
Based on the provided information, Prothena's major customer companies are:
- F. Hoffmann-La Roche Ltd. (and Hoffmann-La Roche Inc.)
- Bristol-Myers Squibb (NYSE: BMY)
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Gene G. Kinney, Ph.D., President and Chief Executive Officer, DirectorDr. Kinney has served as Prothena's President and Chief Executive Officer since September 2016, and as a Director since the same month. Prior to his appointment as CEO, he was the company's Chief Operating Officer for part of 2016, and before that, he held the roles of Chief Scientific Officer and Head of Research and Development from 2012 to 2016. Dr. Kinney was a founding member of Prothena's leadership team when the company spun out of Elan in 2012. His earlier career includes various leadership positions at Elan Pharmaceuticals Inc., where he served as Vice President, Pharmacology, and Senior Vice President of Pharmacological Sciences. He also held responsibility for overseeing nonclinical research at Janssen Alzheimer Immunotherapy R&D, and worked at Merck Research Laboratories as Senior Director, Head of Central Pharmacology, contributing to drug discovery and leading programs for neurodegenerative and psychiatric conditions. Additionally, Dr. Kinney held positions at Bristol Myers Squibb and was an Assistant Professor at the Emory University School of Medicine.
Tran B. Nguyen, Chief Strategy Officer and Chief Financial Officer
Mr. Nguyen has been Prothena's Chief Financial Officer since 2013 and took on the role of Chief Strategy Officer in September 2021. He also served as the Chief Operating Officer from June 2018 to September 2021. With over 25 years of experience in biotech finance, banking, and private equity industries, Mr. Nguyen has a strong background in financial leadership. Before joining Prothena, he held Chief Financial Officer positions at Somaxon Pharmaceuticals, Inc. from 2010 until its acquisition in 2013, and at Metabasis Therapeutics, Inc. from 2009 until its sale in 2010. His experience also includes healthcare investment banking roles at Citi and Lehman Brothers. Mr. Nguyen's background reflects a pattern of managing companies involved in acquisitions, having been CFO at two biotechs through sale transactions. He currently serves on the board of directors of Rain Oncology Inc. and previously served on the board of Sierra Oncology, Inc.
Chad J. Swanson, Ph.D., Chief Development Officer
Dr. Swanson was appointed Chief Development Officer of Prothena in September 2024, joining the executive leadership team. He first came to Prothena in January 2023 as Senior Vice President and Head of Clinical Development. Dr. Swanson is a neuropharmacologist with over 20 years of industry experience. Before his tenure at Prothena, he was the Executive Director of Clinical Research in the Alzheimer's Disease Brain Health group at Eisai, Inc., where he led the lecanemab program as the International Project Team Leader.
Michael J. Malecek, Chief Legal Officer and Company Secretary
Mr. Malecek serves as Prothena's Chief Legal Officer and Company Secretary.
Wagner M. Zago, Chief Scientific Officer
Mr. Zago holds the position of Chief Scientific Officer at Prothena.
AI Analysis | Feedback
The key risks to Prothena's business are primarily centered around the challenging and high-stakes nature of biopharmaceutical development, particularly in neurodegenerative and rare diseases.
- Clinical Trial Failure and Regulatory Approval Risk: Prothena, as a late-stage clinical company, faces significant inherent risks associated with its investigational therapies failing to meet primary or secondary endpoints in clinical trials or subsequently failing to obtain regulatory approval. This risk was recently demonstrated by the discontinuation of its wholly-owned birtamimab program in May 2025, following its failure to meet endpoints in the Phase 3 AFFIRM-AL clinical trial for AL amyloidosis. This setback resulted in a strategic pivot for the company, including a substantial workforce reduction, and heightened reliance on the success of its remaining pipeline, particularly PRX012 for Alzheimer's disease, an area known for high clinical trial failure rates.
- Reliance on a Limited and Concentrated Pipeline: Following the discontinuation of its birtamimab program, Prothena's pipeline has become more concentrated. This increases the company's dependence on the successful development and eventual commercialization of a smaller number of key assets, such as PRX012. Any significant setback or delay in these remaining programs would have a disproportionately large impact on Prothena's valuation, financial performance, and future prospects.
- Dependence on Strategic Collaborations: Prothena relies significantly on its license, development, and commercialization agreements with major pharmaceutical partners, including F. Hoffmann-La Roche Ltd. and Bristol-Myers Squibb, for the advancement of several pipeline candidates like prasinezumab and PRX019. These collaborations are crucial for funding, development, and potential commercialization. Any changes in these strategic relationships, such as shifts in partner priorities, funding commitments, or adverse outcomes in partnered clinical trials (like the missed primary endpoint for prasinezumab in the PADOVA study), could negatively affect Prothena's business and financial standing.
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AI Analysis | Feedback
Prothena Corporation plc (PRTA) focuses on developing therapies for several life-threatening diseases, each representing a significant addressable market.
Addressable Markets for Prothena's Main Products:
- Birtamimab (AL amyloidosis): The global AL amyloidosis therapeutics market was valued at approximately $3.81 billion in 2024 across the top 7 major markets (US, EU4, UK, and Japan), and is projected to reach about $15.00 billion by 2035. The U.S. market alone for AL amyloidosis therapeutics is estimated at $0.86 billion in 2024, with a projection to reach approximately $1.22 billion by 2030.
- Prasinezumab (Parkinson's disease): The global Parkinson's disease therapeutics market was valued at $6.2 billion in 2024 and is projected to reach $13.3 billion by 2034. The Parkinson's disease treatment market in the United States is expected to reach a projected revenue of $2.60 billion by 2030. Another estimate places the US Parkinson's Disease Therapeutics Market Size at $1.45 billion in 2024, projected to grow to $3.50 billion by 2035.
- PRX004 (Transthyretin amyloidosis - ATTR amyloidosis): The global transthyretin amyloidosis treatment market was valued at $7.81 billion in 2024 and is expected to reach $17.80 billion by 2032. In the U.S., the transthyretin amyloidosis treatment market size was valued at $3.11 billion in 2024 and is expected to reach $6.92 billion by 2032.
- PRX005, PRX012, and dual Aß-Tau vaccine (Alzheimer's disease): The global Alzheimer's disease market in the 7MM (US, EU4, UK, and Japan) was valued at approximately $3.61 billion in 2023 and is projected to reach $34.33 billion by 2034. The Alzheimer's disease market is estimated to grow from $11.3 billion in 2024 to $12.4 billion in 2025 and $29.4 billion by 2035 globally. In the United States, the Alzheimer's drugs market size was worth $1.62 billion in 2022.
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Here are 3-5 expected drivers of future revenue growth for Prothena (PRTA) over the next 2-3 years:- Milestone Payments from Roche Collaboration for Prasinezumab: Prothena is eligible for significant milestone payments as its partner, Roche, advances prasinezumab into Phase III development for early-stage Parkinson's disease, a stage initiated in the fourth quarter of 2025. Prothena could receive up to $620 million in additional milestone payments from this collaboration.
- Milestone Payments from Novo Nordisk Collaboration for Coramitug: Prothena anticipates further milestone payments from its collaboration with Novo Nordisk for coramitug, an amyloid depleter antibody in Phase III development for ATTR cardiomyopathy. A clinical milestone payment is specifically expected in the first half of 2026 upon meeting prespecified enrollment targets in the ongoing Phase III CLEOPATTRA study. Prothena is eligible for up to $1.13 billion in total development and sales milestones from this partnership.
- Milestone Payments from Bristol-Myers Squibb (BMS) Collaborations for PRX019 and BMS-986446: The advancement of programs partnered with BMS is a key revenue driver. Prothena expects to complete the Phase I trial for PRX019 in 2026, which could trigger a milestone payment if BMS decides to pursue further development. Additionally, the Phase II TargetTau-1 clinical trial for BMS-986446 in early Alzheimer's disease, which was fully enrolled in 2025, is expected to complete in the first half of 2027, potentially leading to further development milestones. Prothena is eligible for up to an additional $1.7 billion for regulatory and commercial milestone payments across multiple programs in this collaboration.
- Upfront and Milestone Payments from Potential New Collaboration and Licensing Deals: Prothena continues to engage in business development activities, including exploring partnership opportunities for its wholly-owned assets such as PRX012-TfR and its novel preclinical platforms like TDP-43 CYTOPE. Any new collaboration or licensing agreements for these programs could result in upfront payments and future development milestones, contributing to revenue growth within the forecast period.
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Share Repurchases
- Prothena's board authorized a share repurchase program of up to $100.0 million, announced on February 27, 2026.
- This program is set to expire on December 31, 2026.
- As of December 31, 2025, prior to any repurchases under this plan, Prothena held $308.4 million in cash, cash equivalents, and restricted cash with no debt.
Share Issuance
- The number of ordinary shares outstanding was approximately 53.7 million as of February 9, 2024.
- The number of ordinary shares outstanding was approximately 53.8 million as of February 20, 2025, and February 12, 2026.
- Prothena filed a registration statement (S-8) to enable equity awards under its amended 2018 Long Term Incentive Plan.
Inbound Investments
- In 2024, Prothena received an $80 million payment from Bristol Myers Squibb (BMS) for the exclusive global license for PRX019.
- In 2023, Bristol Myers Squibb opted into global rights for BMS-986446 (formerly PRX005), triggering a $55 million milestone payment.
- Prothena anticipates up to $105 million in aggregate clinical milestone payments from strategic partners (Novo Nordisk and Bristol Myers Squibb) in 2026.
Capital Expenditures
- Capital expenditures were reported as $0.30 million in 2024.
- Capital expenditures were reported as $2.77 million in 2023.
- Capital expenditures were reported as $0.46 million in 2022.
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Peer Comparisons
| Peers to compare with: |
Financials
| Median | |
|---|---|
| Name | |
| Mkt Price | 133.76 |
| Mkt Cap | 20.4 |
| Rev LTM | 2,673 |
| Op Inc LTM | 284 |
| FCF LTM | 240 |
| FCF 3Y Avg | 40 |
| CFO LTM | 276 |
| CFO 3Y Avg | 68 |
Growth & Margins
| Median | |
|---|---|
| Name | |
| Rev Chg LTM | 47.4% |
| Rev Chg 3Y Avg | 24.9% |
| Rev Chg Q | 55.5% |
| QoQ Delta Rev Chg LTM | 10.8% |
| Op Inc Chg LTM | 12.2% |
| Op Inc Chg 3Y Avg | 1.7% |
| Op Mgn LTM | 17.5% |
| Op Mgn 3Y Avg | 1.3% |
| QoQ Delta Op Mgn LTM | 1.7% |
| CFO/Rev LTM | 16.7% |
| CFO/Rev 3Y Avg | 8.0% |
| FCF/Rev LTM | 14.4% |
| FCF/Rev 3Y Avg | 0.3% |
Valuation
| Median | |
|---|---|
| Name | |
| Mkt Cap | 20.4 |
| P/S | 12.0 |
| P/Op Inc | 4.5 |
| P/EBIT | 5.8 |
| P/E | 9.0 |
| P/CFO | 3.6 |
| Total Yield | -0.6% |
| Dividend Yield | 0.0% |
| FCF Yield 3Y Avg | -4.1% |
| D/E | 0.0 |
| Net D/E | -0.0 |
Returns
| Median | |
|---|---|
| Name | |
| 1M Rtn | 5.9% |
| 3M Rtn | -6.8% |
| 6M Rtn | 7.9% |
| 12M Rtn | 49.1% |
| 3Y Rtn | 9.9% |
| 1M Excs Rtn | -5.7% |
| 3M Excs Rtn | -13.8% |
| 6M Excs Rtn | 0.8% |
| 12M Excs Rtn | 2.7% |
| 3Y Excs Rtn | -62.1% |
Price Behavior
Price Behavior
| Market Price | $11.18 | |
| Market Cap ($ Bil) | 0.6 | |
| First Trading Date | 12/21/2012 | |
| Distance from 52W High | -2.9% | |
| 50 Days | 200 Days | |
| DMA Price | $9.94 | $9.40 |
| DMA Trend | up | up |
| Distance from DMA | 12.5% | 18.9% |
| 3M | 1YR | |
| Volatility | 46.1% | 57.8% |
| Downside Capture | 0.67 | 0.57 |
| Upside Capture | 191.69 | 126.76 |
| Correlation (SPY) | 43.1% | 20.6% |
PRTA Betas & Captures as of 4/30/2026
[1] Upside and downside betas calculated using positive and negative benchmark daily returns respectively
| 1M | 2M | 3M | 6M | 1Y | 3Y | |
|---|---|---|---|---|---|---|
| Beta | 1.44 | 1.20 | 1.37 | 1.23 | 0.93 | 1.01 |
| Up Beta | 1.59 | 0.84 | 1.30 | 1.20 | 0.25 | 0.52 |
| Down Beta | 0.17 | -0.25 | 0.24 | -0.01 | 0.90 | 1.38 |
| Up Capture | 136% | 237% | 216% | 178% | 112% | 40% |
| Bmk +ve Days | 15 | 22 | 31 | 66 | 141 | 428 |
| Stock +ve Days | 14 | 22 | 30 | 55 | 119 | 348 |
| Down Capture | 212% | 120% | 135% | 152% | 125% | 110% |
| Bmk -ve Days | 4 | 18 | 30 | 56 | 108 | 321 |
| Stock -ve Days | 8 | 21 | 33 | 69 | 128 | 396 |
[1] Upside and downside betas calculated using positive and negative benchmark daily returns respectively
Based On 1-Year Data
| Annualized Return | Annualized Volatility | Sharpe Ratio | Correlation with PRTA | |
|---|---|---|---|---|
| PRTA | 39.2% | 58.6% | 0.81 | - |
| Sector ETF (XLV) | 7.2% | 15.7% | 0.25 | 24.8% |
| Equity (SPY) | 28.5% | 12.5% | 1.78 | 20.8% |
| Gold (GLD) | 40.6% | 27.2% | 1.23 | 9.7% |
| Commodities (DBC) | 50.9% | 18.0% | 2.20 | -2.7% |
| Real Estate (VNQ) | 12.8% | 13.5% | 0.65 | 15.8% |
| Bitcoin (BTCUSD) | -14.2% | 42.1% | -0.25 | 18.9% |
Smart multi-asset allocation framework can stack odds in your favor. Learn How
Based On 5-Year Data
| Annualized Return | Annualized Volatility | Sharpe Ratio | Correlation with PRTA | |
|---|---|---|---|---|
| PRTA | -16.0% | 78.0% | 0.08 | - |
| Sector ETF (XLV) | 5.3% | 14.6% | 0.19 | 28.8% |
| Equity (SPY) | 12.7% | 17.1% | 0.58 | 30.6% |
| Gold (GLD) | 21.0% | 17.9% | 0.96 | 7.1% |
| Commodities (DBC) | 13.9% | 19.1% | 0.60 | 6.1% |
| Real Estate (VNQ) | 3.5% | 18.8% | 0.09 | 26.7% |
| Bitcoin (BTCUSD) | 8.7% | 56.1% | 0.37 | 16.3% |
Smart multi-asset allocation framework can stack odds in your favor. Learn How
Based On 10-Year Data
| Annualized Return | Annualized Volatility | Sharpe Ratio | Correlation with PRTA | |
|---|---|---|---|---|
| PRTA | -12.8% | 75.9% | 0.17 | - |
| Sector ETF (XLV) | 9.3% | 16.5% | 0.45 | 31.8% |
| Equity (SPY) | 14.9% | 17.9% | 0.71 | 31.5% |
| Gold (GLD) | 13.7% | 16.0% | 0.71 | 4.7% |
| Commodities (DBC) | 9.5% | 17.7% | 0.45 | 12.2% |
| Real Estate (VNQ) | 5.7% | 20.7% | 0.24 | 22.2% |
| Bitcoin (BTCUSD) | 68.4% | 66.9% | 1.07 | 9.5% |
Smart multi-asset allocation framework can stack odds in your favor. Learn How
Earnings Returns History
Expand for More| Forward Returns | |||
|---|---|---|---|
| Earnings Date | 1D Returns | 5D Returns | 21D Returns |
| 2/19/2026 | -0.1% | -4.3% | -3.1% |
| 11/6/2025 | 4.8% | 1.0% | 2.4% |
| 8/4/2025 | 1.3% | 10.5% | 20.9% |
| 5/8/2025 | 4.6% | -5.4% | -26.1% |
| 2/20/2025 | 2.0% | -0.8% | -15.0% |
| 11/12/2024 | -0.7% | -19.1% | -20.4% |
| 8/8/2024 | 4.4% | 6.0% | 3.7% |
| 5/8/2024 | -4.5% | -2.8% | -8.3% |
| ... | |||
| SUMMARY STATS | |||
| # Positive | 11 | 10 | 10 |
| # Negative | 13 | 14 | 14 |
| Median Positive | 4.4% | 4.4% | 6.0% |
| Median Negative | -4.0% | -4.4% | -13.5% |
| Max Positive | 12.0% | 51.0% | 93.8% |
| Max Negative | -8.3% | -19.1% | -26.1% |
SEC Filings
Expand for More| Report Date | Filing Date | Filing |
|---|---|---|
| 12/31/2025 | 02/27/2026 | 10-K |
| 09/30/2025 | 11/06/2025 | 10-Q |
| 06/30/2025 | 08/04/2025 | 10-Q |
| 03/31/2025 | 05/08/2025 | 10-Q |
| 12/31/2024 | 02/27/2025 | 10-K |
| 09/30/2024 | 11/12/2024 | 10-Q |
| 06/30/2024 | 08/08/2024 | 10-Q |
| 03/31/2024 | 05/08/2024 | 10-Q |
| 12/31/2023 | 02/22/2024 | 10-K |
| 09/30/2023 | 11/02/2023 | 10-Q |
| 06/30/2023 | 08/03/2023 | 10-Q |
| 03/31/2023 | 05/04/2023 | 10-Q |
| 12/31/2022 | 02/28/2023 | 10-K |
| 09/30/2022 | 11/03/2022 | 10-Q |
| 06/30/2022 | 08/08/2022 | 10-Q |
| 03/31/2022 | 05/05/2022 | 10-Q |
Insider Activity
Expand for More| # | Owner | Title | Holding | Action | Filing Date | Price | Shares | Transacted Value | Value of Held Shares | Form |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Ecor1, Capital, Llc | See Note | Sell | 5062025 | 7.64 | 1,984,053 | 15,164,712 | 40,544,619 | Form | |
| 2 | Ecor1, Capital, Llc | See Note | Sell | 5062025 | 8.11 | 977,693 | 7,930,166 | 59,118,961 | Form | |
| 3 | Ecor1, Capital, Llc | See Note | Sell | 5062025 | 8.36 | 3,317,938 | 27,744,929 | 69,123,978 | Form | |
| 4 | Scully, William P | Direct | Buy | 5022025 | 12.79 | 100,000 | 1,279,040 | 9,413,645 | Form | |
| 5 | Scully, William P | Direct | Buy | 5022025 | 13.01 | 32,000 | 416,393 | 8,460,503 | Form |
Industry Resources
External Quote Links
| Y Finance | Barrons |
| TradingView | Morningstar |
| SeekingAlpha | ValueLine |
| Motley Fool | Robinhood |
| CNBC | Etrade |
| MarketWatch | Unusual Whales |
| YCharts | Perplexity Finance |
| FinViz |
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