Protagonist Therapeutics Inc. Common Stock (PTGX)

FairStock Score: 22/100 — RISKY

Key Financials

AI Analysis

AI-generated, general educational analysis — not personal investment advice.

I approach Protagonist with Graham's caution and Buffett's question: what is this business worth, and what protects it? It is a small biotechnology firm, with 141 employees, developing oral peptides for psoriasis and a Phase 3 injectable for polycythemia vera. The science may be valuable, but drug development is not a durable moat until approval and reimbursement create repeatable revenue. The filed numbers are erratic. In fiscal 2023, the year ended 2023-12-31, revenue was $60.0 million and net loss was $79.0 million. In fiscal 2024, the year ended 2024-12-31, revenue was $434.4 million and net income was $275.2 million. In fiscal 2025, the year ended 2025-12-31, revenue fell to $46.0 million and net loss was $130.1 million. The latest filed quarter, fiscal Q2 2026, the quarter ended 2026-06-30, showed revenue of $213.5 million and net income of $162.8 million. One quarter does not make a trend. The balance sheet looks conservative, with debt-to-equity of 0.01, a Piotroski F-Score of 7/9, and an Altman Z-Score of 123.59. Yet returns are modest: ROE 10.98%, ROCE 4.55%, and free cash flow yield 1.5%. At the 2026-10-13 close of $138.49, the FairStock P/E is 134.46, P/B is 10.64, EV/EBITDA is 142.79, and the Graham Number is $17.36, a margin of safety of -697.75%. FairStock's Lynch category is TURNAROUND because the latest filed year was a loss after earlier profits. I would want several quarters of durable product revenue before paying such a premium. This is a speculative bet on clinical and commercial success, not a Graham bargain.

In plain English: Protagonist Therapeutics is a small drug company developing treatments for psoriasis and a rare blood disease. Its sales and profits have swung sharply: it lost money in fiscal 2025 after a profitable fiscal 2024, but the latest quarter was strongly profitable. At the 2026-10-13 price, the shares look expensive compared with the company's recent profit, book value, and cash generation, even though growth has been rapid.

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Data as of 2026-10-13 close · note generated 2026-10-15 · model deepseek-flash

Sources (SEC EDGAR): fiscal Q2 2026 10-Q (period ended 2026-06-30) · fiscal Q1 2026 10-Q (period ended 2026-03-31) · fiscal Q3 2025 10-Q (period ended 2025-09-30) · fiscal Q2 2025 10-Q (period ended 2025-06-30) · FY2025 10-K (period ended 2025-12-31) · FY2024 10-K (period ended 2024-12-31) · FY2023 10-K (period ended 2023-12-31)

Fundamentals from company filings and market-data providers; prices are end-of-day, not real-time. AI-generated analysis is general and educational — not personal investment advice. Scoring methodology · Score test · Disclaimer