PROTHENA CORP PUBLIC LTD CO
PRTA · Pharmaceutical Preparations · 52.4M shares · +7%/yr ↑ dilution · EDGAR filings ↗
Reference price $7.90 · est. market cap ~$414M — last insider purchase, 2026-06-16 (estimated from the dated SEC Form 4 price × shares outstanding — not a live quote)
Grade
D44Clinical/early-stage biotech — neuroscience clinical (post-collaboration), well-funded.
Strengths
- Liquidity — current ratio 7.7 (72nd)
Risks
- Pre-revenue, deep losses — per metrics
- Pre-revenue/clinical-stage — history of losses & need for capital per risk factors
- Binary clinical & funding risk — per 10-K
Notable findings
- Net lossNet loss (net margin -2520.6%)
- Strong balance sheetStrong balance sheet — $308M cash & investments
- Insider buyingInsider buying — 5 open-market buy(s) by 1 insider(s) (~$3M, last 6mo) Form 4 ↗
- Revenue declineRevenue -92.8% YoY
Quarterly revenue
Last 4 quarters · from SEC filings.
Key metrics
Operating margin
-2216.4%
Net margin
-2520.6%
Return on equity
-87.0%
Return on assets
-74.7%
Revenue growth (QoQ)
-92.8%
Current ratio
7.7×
EBITDA
-$214M
Tangible book value
$280M
Cash & investments
$308M
Stock comp / revenue
388.7%
Insider transactions · last 18 months
| Date | Insider | Type | Shares | Price |
|---|---|---|---|---|
| 2026-06-16 | SCULLY WILLIAM P | Buy | 20K | $7.90 |
| 2026-06-15 | SCULLY WILLIAM P | Gift | 325K | — |
| 2026-06-11 | SCULLY WILLIAM P | Buy | 125K | $8.17 |
| 2026-06-04 | SCULLY WILLIAM P | Buy | 50K | $9.31 |
| 2026-06-02 | SCULLY WILLIAM P | Buy | 50K | $9.43 |
| 2026-05-22 | SCULLY WILLIAM P | Buy | 100K | $9.81 |
| 2025-07-28 | Kinney Gene G. | Grant | 140K | — |
| 2025-07-28 | Malecek Michael J | Grant | 80K | — |
| 2025-07-28 | Zago Wagner M. | Grant | 85K | — |
| 2025-07-28 | Walker Karin L | Grant | 25K | — |
| 2025-07-28 | Swanson Chad J. | Grant | 85K | — |
| 2025-07-28 | Smith Brandon S. | Grant | 130K | — |
| 2025-07-28 | Nguyen Tran | Grant | 95K | — |
| 2025-05-06 | EcoR1 Capital, LLC | Sell | 2.0M | $7.64 |
| 2025-05-05 | EcoR1 Capital, LLC | Sell | 978K | $8.11 |
| 2025-05-02 | EcoR1 Capital, LLC | Sell | 3.3M | $8.36 |
| 2025-01-15 | SCULLY WILLIAM P | Gift | 12K | — |
| 2025-01-14 | SCULLY WILLIAM P | Buy | 100K | $12.79 |
| 2025-01-03 | SCULLY WILLIAM P | Gift | 1.0K | — |
| 2025-01-02 | SCULLY WILLIAM P | Gift | 13K | — |
| 2024-12-31 | SCULLY WILLIAM P | Buy | 800 | $13.39 |
| 2024-12-31 | SCULLY WILLIAM P | Buy | 30K | $12.99 |
| 2024-12-31 | SCULLY WILLIAM P | Buy | 1.2K | $13.37 |
All non-derivative Form 4 activity (SEC), newest first.
Notable events (8-K)
Recent filings
| Form | Filed | Period | Accession |
|---|---|---|---|
| 8-K | 2026-05-15 | 2026-05-14 | 0001193125-26-226968 ↗ |
| 10-Q | 2026-05-07 | 2026-03-31 | 0001559053-26-000017 ↗ |
| 8-K | 2026-05-07 | 2026-05-07 | 0001559053-26-000016 ↗ |
| 8-K | 2026-02-27 | 2026-02-27 | 0001559053-26-000009 ↗ |
| 10-K | 2026-02-27 | 2025-12-31 | 0001559053-26-000008 ↗ |
| 8-K | 2026-02-19 | 2026-02-19 | 0001559053-26-000003 ↗ |
| 8-K | 2025-12-12 | 2025-12-10 | 0001559053-25-000049 ↗ |
| 8-K | 2025-11-19 | 2025-11-19 | 0001559053-25-000047 ↗ |
| 8-K | 2025-11-06 | 2025-11-06 | 0001559053-25-000042 ↗ |
| 10-Q | 2025-11-06 | 2025-09-30 | 0001559053-25-000044 ↗ |
| 8-K | 2025-08-27 | 2025-08-27 | 0001193125-25-189765 ↗ |
| 8-K | 2025-08-06 | 2025-08-06 | 0001193125-25-174061 ↗ |