PRTA short interest
Prothena Corporation plc · Healthcare · Biotechnology · settlement date 2026-09-30
| Shares short | 8,010,864 |
|---|---|
| Change vs prior report | -533,800 (-6.2%) |
| Change over six months | +14.2% |
| Days to cover | 13.79 (sector: 3.78) |
| Average daily volume | 580,885 |
| Rank in Healthcare | #48 of 922 by days to cover |
PRTA short interest, last 12 months
| Settlement | Shares short | Change | Days to cover | Avg daily volume |
|---|---|---|---|---|
| 2026-09-30 | 8,010,864 | -6.2% | 13.79 | 580,885 |
| 2026-09-15 | 8,544,664 | +0.6% | 26.53 | 322,027 |
| 2026-08-31 | 8,495,796 | -0.6% | 24.85 | 341,894 |
| 2026-08-14 | 8,545,127 | +4.6% | 19.56 | 436,939 |
| 2026-07-31 | 8,172,438 | -0.3% | 13.96 | 585,253 |
| 2026-07-15 | 8,196,964 | -2.1% | 16.40 | 499,741 |
| 2026-06-30 | 8,369,568 | +6.4% | 11.02 | 759,430 |
| 2026-06-15 | 7,866,857 | +1.7% | 15.98 | 492,334 |
| 2026-05-29 | 7,737,902 | +9.0% | 13.85 | 558,736 |
| 2026-05-15 | 7,097,854 | +3.3% | 12.96 | 547,700 |
| 2026-04-30 | 6,871,465 | -2.9% | 18.33 | 374,817 |
| 2026-04-15 | 7,076,832 | +0.9% | 15.33 | 461,513 |
| 2026-03-31 | 7,016,080 | -0.4% | 12.32 | 569,553 |
| 2026-03-13 | 7,044,790 | +2.8% | 11.20 | 628,888 |
| 2026-02-27 | 6,854,767 | -3.2% | 17.22 | 398,107 |
| 2026-02-13 | 7,083,043 | +0.3% | 18.12 | 390,797 |
| 2026-01-30 | 7,063,694 | -0.1% | 13.90 | 508,225 |
| 2026-01-15 | 7,069,471 | +7.4% | 14.42 | 490,187 |
| 2025-12-31 | 6,584,532 | +40.1% | 7.96 | 827,377 |
| 2025-12-15 | 4,699,126 | +1.3% | 6.78 | 692,839 |
| 2025-11-28 | 4,639,338 | -0.4% | 9.02 | 514,550 |
| 2025-11-14 | 4,657,490 | +12.4% | 7.38 | 631,094 |
| 2025-10-31 | 4,144,115 | +7.4% | 8.06 | 513,944 |
| 2025-10-15 | 3,857,015 | +0.3% | 5.37 | 718,695 |
| 2025-09-30 | 3,845,694 | +2.2% | 5.03 | 764,721 |
import finzdata as yf
yf.Ticker("PRTA").short_interest # every report since 2017
yf.Client().short_interest(["PRTA"], start="2018-01-01")Healthcare short interest · PRTA price history · Who owns PRTA · All short interest