Is PRTA halal?
Prothena Corporation plc
Not halal
Prothena Corporation plc did not pass AAOIFI screening. The failed check is shown below.
Checked: 13 October 2026
Exchange
NASDAQ
Price
8.35
Day
-1.76%
Market cap
$432.8M
Industry
Biotechnology
Sector
Healthcare
What the company does
Prothena (Ireland) develops drugs for brain and protein-misfolding diseases: Parkinson's (prasinezumab with Roche), Alzheimer's and amyloidosis. Money comes from partner payments and investors.
What was checked
The AAOIFI standard has four steps: business activity first, then three financial ratios. Fail one and the stock is not halal.
Business activity
No prohibited activity
Interest-bearing debt / market cap
limit 30%
Interest-bearing debt $0 ÷ 36-month average market cap $826.41M = 0.0%
0.0%
Pass
Cash & investments / market cap
limit 30%
Cash + interest-bearing securities $288.19M ÷ 36-month average market cap $826.41M = 34.9%
34.9%
Fail
Non-compliant income / total revenue
limit 5%
Interest income $14.14M ÷ annual revenue $9.68M (2025) = 146.0%
146.0%
Fail
Figures from the company's filings (2026-06-30), USD. Market cap is a 36-month average (the S&P Shariah index approach), so a one-day price move does not flip the verdict. Today's market cap: $432.77M.
In the lists
- In the S&P 500
- Not in the S&P 500
- Held by funds
- Not held by any tracked fund
Halal stocks in the same industry
The largest halal stocks in Biotechnology — for comparison.
Related articles
- Halal investingBlogHaram revenue you can't see from the industry label: pork, weapons, casinosPork hides under "Packaged Foods", weapons under "Aerospace & Defense". What automated screening misses and how we catch it by hand.
- Halal investingBlogWhy a company's cash affects whether its stock is halalLots of cash sounds like a good sign — but halal screening checks it separately. What counts, what doesn't, and where we are stricter than AAOIFI.
- Halal investingBlogAAOIFI Shariah Standard No. 21 in plain languageThe most widely used standard for halal stock screening: the two-step test, the three ratios and how it differs from other methods.
Halal is the first question. The second: when to enter?
Our scanner watches 1454 halal stocks around the clock and fires a signal with entry, TP and SL when a technical setup completes. The full signal history — with outcomes — is public.
This is neither investment advice nor a fatwa. Screening is based on public financial statements and AAOIFI standard No. 21; data may lag. For a personal decision consult your own scholar.