Which indexes is Prothena in?

Prothena is in 2 of the 57 indexes we track. Its largest weight is 0.01% in the Russell 2000, where it ranks #1625 of 1963.

Ticker

PRTA (Nasdaq)

Country

United States

Sector

Health Care

Size

Small cap (market cap $300 million–2 billion; exact figure in the ranking)

Data as of

15 Oct 2026

Member of 2 indexes

Source: each index's own source, listed on its page. How we source this. Weights are estimates where marked. This page is refreshed when a membership changes or a weight moves by more than 10%; each index page has the daily figures.

Prothena across every index we track

Lit tiles are the indexes Prothena belongs to; the shade is its weight there.

Americas

1. S&P Mervalnot in
2. Ibovespanot in
3. S&P/TSX Compositenot in
4. S&P IPSAnot in
5. S&P/BMV IPCnot in
6. S&P 500not in
7. Nasdaq-100not in
8. Dow Jonesnot in
9. Russell 20000.01%
10. Nasdaq Composite0.00%
11. NYSE Compositenot in

Europe

1. Euro Stoxx 50not in
2. ATXnot in
3. BEL 20not in
4. OMX Copenhagen 20not in
5. OMX Tallinnnot in
6. OMX Helsinki 25not in
7. CAC 40not in
8. DAXnot in
9. OMX Iceland 15not in
10. ISEQ 20not in
11. FTSE MIBnot in
12. OMX Riganot in
13. OMX Vilniusnot in
14. LuxXnot in
15. AEXnot in
16. AMXnot in
17. AMS Next 20not in
18. OSEBXnot in
19. WIG20not in
20. PSInot in
21. MOEX Russianot in
22. IBEX 35not in
23. IBEX Medium Capnot in
24. IBEX Small Capnot in
25. OMX Stockholm 30not in
26. SMInot in
27. BIST 100not in
28. FTSE 100not in

Asia-Pacific

1. S&P/ASX 200not in
2. Shanghai Compositenot in
3. Hang Sengnot in
4. Nifty 50not in
5. IDX Compositenot in
6. Nikkei 225not in
7. S&P/NZX 50not in
8. KSE 100not in
9. Straits Times Indexnot in
10. KOSPInot in
11. VN-Indexnot in

Middle East & Africa

1. EGX 30not in
2. TA-35not in
3. ASE Generalnot in
4. QE Indexnot in
5. TASInot in
6. JSE Top 40not in
7. ADX Generalnot in

Fewermore

Neighbours by weight

Not in

• Prothena is not in the S&P 500. It is in the Russell 2000 instead; the two do not share members by design.
• Prothena is not in the Nasdaq-100.
• Prothena is not in the Dow Jones.
• Prothena is not in the NYSE Composite.

Among the indexes we track for United States.