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EOD US-equity data for investors and AI agents

Data is end-of-day, not real-time, and not investment advice

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PRTA short positioning

Twice-monthly snapshots of open short positions.

Settlement 2026-07-31
Short % of Float23.1%35,445,100 float shares
Days to Cover14.0585,253 average daily volume
Open Short Position8,172,438Prothena Corporation plc Ordin
Change vs Previous-24,526-0.3%

Short interest history

Twice-monthly snapshots of open short positions.

SettlementShort PositionChangeChange %Days to CoverShort % Float
Jul 31, 20268,172,438-24,526-0.3%14.023.1%
Jul 15, 20268,196,964-172,604-2.1%16.423.1%
Jun 30, 20268,369,568+502,711+6.4%11.023.6%

Short interest is an open-position snapshot published twice monthly. It is not daily short-sale volume.

Daily off-exchange short volume

FINRA-reported short-sale transaction flow for the last 30 calendar days.

Trade DateShort VolumeShort ExemptFINRA TotalShort Volume %Facilities
Aug 21, 202661,0330117,74551.8%3
Aug 20, 202697,6190114,90385.0%3
Aug 19, 202650,9470103,99949.0%3
Aug 18, 202641,363068,59060.3%3
Aug 17, 202677,2550124,07462.3%3
Aug 14, 202678,4550103,33275.9%3
Aug 13, 202668,4170101,89467.1%3
Aug 12, 202648,134077,68762.0%3
Aug 11, 202696,371500162,62759.3%2
Aug 10, 2026179,2420261,89768.4%3
Aug 7, 202684,5400118,09471.6%3
Aug 6, 202694,264700134,99569.8%3
Aug 5, 202674,43028122,11161.0%3
Aug 4, 202665,017090,58671.8%3
Aug 3, 2026112,3590155,91572.1%3
Jul 31, 2026140,9670180,06678.3%2
Jul 30, 202696,2490143,59067.0%2
Jul 29, 202683,7790159,94452.4%3
Jul 28, 2026135,133100269,66150.1%3
Jul 27, 2026130,8980191,99568.2%3
Jul 24, 2026101,1660149,81167.5%3

Daily short volume is transaction flow reported through FINRA facilities. It does not measure open short positions and is not consolidated exchange-wide volume.