PRTA
Prothena Corporation plc
8.80$
+2.7%
vs. previous close
Closing price · As of: Oct 9, 2026
Statements
Ratios
Valuation ratios (P/E, P/S, EV/EBITDA and the other multiples) are based on the closing price at the end of each period, not on the current price. Margins and returns are shown in percent, multiples without a unit, per-share figures in the reporting currency, net debt in millions.
Tick rows to compare them in a chart (up to 4)
| Line item | Q3 16 | Q4 16 | Q1 17 | Q2 17 | Q3 17 | Q4 17 | Q1 18 | Q2 18 | Q3 18 | Q4 18 | Q1 19 | Q2 19 | Q3 19 | Q4 19 | Q1 20 | Q2 20 | Q3 20 | Q4 20 | Q1 21 | Q2 21 | Q3 21 | Q4 21 | Q1 22 | Q2 22 | Q3 22 | Q4 22 | Q1 23 | Q2 23 | Q3 23 | Q4 23 | Q1 24 | Q2 24 | Q3 24 | Q4 24 | Q1 25 | Q2 25 | Q3 25 | Q4 25 | Q1 26 | Q2 26 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Valuation | ||||||||||||||||||||||||||||||||||||||||
| – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | 52.5 | 34.4 | 25.4 | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | |
| 1,733.7 | 1,613.7 | 1,902.1 | 74.8 | 90.4 | 52.4 | 51.6 | 609.5 | 527.3 | 429.9 | 527.7 | 527.0 | 413.8 | 774.4 | 555.3 | 525.8 | 532.9 | 561.6 | 1,158.6 | 40.1 | 18.3 | 11.5 | 8.5 | 8.9 | 552.5 | 60.4 | 46.4 | 63.0 | 19.9 | 21.3 | 14.9 | 5.2 | 6.7 | 5.5 | 4.8 | 31.8 | 44.8 | 53.4 | 9.1 | 9.4 | |
| 5.1 | 4.7 | 4.0 | 4.2 | 5.6 | 3.5 | 3.5 | 1.6 | 1.5 | 1.3 | 1.5 | 1.4 | 1.1 | 2.3 | 1.7 | 1.8 | 1.9 | 2.6 | 4.3 | 8.5 | 7.4 | 4.9 | 3.9 | 3.1 | 7.0 | 5.2 | 4.2 | 6.2 | 4.5 | 3.5 | 2.7 | 1.9 | 1.7 | 1.5 | 1.5 | 1.0 | 1.8 | 1.8 | 1.7 | 1.8 | |
| 1,456.7 | 1,332.6 | 1,505.1 | 61.0 | 75.1 | 38.6 | 37.3 | 136.6 | 105.4 | -16.1 | 108.1 | 36.7 | -98.5 | 319.1 | 103.4 | 113.5 | 120.2 | 221.8 | 771.7 | 33.6 | 15.3 | 8.6 | 5.8 | 5.4 | 457.5 | 47.3 | 34.0 | 51.6 | 15.1 | 14.6 | 8.8 | 2.6 | 2.9 | 2.1 | 1.8 | -3.9 | 16.9 | 21.9 | 3.4 | 4.1 | |
| – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | 40.1 | 23.7 | 16.6 | 301.8 | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | |
| – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | 38.1 | 25.0 | 19.4 | 78.3 | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | |
| -5.5% | -7.9% | -7.5% | -7.6% | -5.5% | -9.3% | -8.9% | -5.5% | -9.1% | -7.3% | -3.3% | -20.4% | -19.8% | -8.5% | -13.9% | -15.7% | -19.0% | -16.8% | -9.0% | -1.5% | 2.6% | 4.0% | 5.2% | 1.3% | -4.5% | -3.4% | -4.7% | -3.6% | -3.2% | -7.0% | -12.2% | -8.9% | -17.3% | -20.1% | -19.6% | -58.7% | -35.7% | -31.7% | -15.5% | -11.9% | |
| Margins | ||||||||||||||||||||||||||||||||||||||||
| -8,093.1% | -11,230.2% | -11,791.2% | -359.2% | -413.1% | -388.9% | -296.0% | -11,039.3% | -8,331.2% | -6,860.9% | -8,627.9% | -7,120.0% | -6,798.3% | -6,145.2% | -6,764.5% | -7,488.0% | -9,191.7% | -8,678.9% | -9,163.8% | -39.3% | 59.5% | 59.0% | 56.1% | 30.8% | -2,242.8% | -151.5% | -178.7% | -208.0% | -38.7% | -141.4% | -97.0% | 44.9% | 53.6% | 100.0% | 100.0% | 100.0% | -145.5% | -208.6% | 46.8% | 43.5% | |
| -11,290.5% | -15,121.8% | -16,053.0% | -531.7% | -572.5% | -564.2% | -610.1% | -22,288.1% | -18,527.0% | -16,634.0% | -14,562.5% | -11,038.5% | -11,326.9% | -10,527.9% | -11,390.2% | -12,023.3% | -14,112.1% | -13,216.2% | -13,760.9% | -107.5% | 37.4% | 35.9% | 32.8% | -3.5% | -3,193.2% | -244.1% | -273.0% | -300.6% | -79.9% | -209.1% | -242.3% | -42.1% | -126.1% | -114.4% | -100.5% | -2,723.2% | -2,166.4% | -2,247.5% | -217.9% | -115.1% | |
| -11,365.4% | -15,176.1% | -16,012.5% | -527.6% | -562.2% | -556.8% | -606.1% | -21,884.4% | -18,277.0% | -16,297.9% | -13,978.9% | -10,435.8% | -10,450.0% | -9,542.6% | -10,452.7% | -11,399.4% | -13,615.8% | -13,029.8% | -14,255.7% | -115.9% | 34.8% | 33.4% | 33.4% | -1.0% | -3,036.0% | -217.0% | -232.2% | -244.5% | -51.9% | -160.9% | -193.2% | -23.4% | -98.9% | -90.5% | -79.9% | -2,929.3% | -2,379.6% | -2,520.6% | -260.9% | -80.7% | |
| -9,524.3% | -12,693.2% | -14,190.9% | -570.0% | -495.4% | -489.9% | -459.2% | -3,344.5% | -4,783.4% | -3,146.0% | -1,733.6% | -10,729.6% | -8,180.6% | -6,575.4% | -7,691.4% | -8,245.7% | -10,147.8% | -9,444.1% | -10,445.3% | -58.8% | 47.9% | 45.9% | 43.8% | 11.4% | -2,462.8% | -202.7% | -217.3% | -224.9% | -63.3% | -149.6% | -181.9% | -46.4% | -116.3% | -111.2% | -94.7% | -1,864.8% | -1,597.0% | -1,690.6% | -140.6% | -111.3% | |
| Returns | ||||||||||||||||||||||||||||||||||||||||
| -33.7% | -43.8% | -33.8% | -29.8% | -34.6% | -37.6% | -40.7% | -58.6% | -53.3% | -48.2% | -40.9% | -27.6% | -27.2% | -28.5% | -31.5% | -38.8% | -48.7% | -60.4% | -53.0% | -24.4% | 14.2% | 14.4% | 15.4% | -0.4% | -38.7% | -18.8% | -21.0% | -24.2% | -11.9% | -26.2% | -34.3% | -8.8% | -24.7% | -25.1% | -25.2% | -93.4% | -95.1% | -87.0% | -48.4% | -15.3% | |
| -28.2% | -34.8% | -28.9% | -25.1% | -28.7% | -30.9% | -27.5% | -37.1% | -34.5% | -31.2% | -27.8% | -18.1% | -17.4% | -18.5% | -20.1% | -24.0% | -28.7% | -33.4% | -32.7% | -16.1% | 11.0% | 11.0% | 11.6% | -0.3% | -28.2% | -15.4% | -17.2% | -19.5% | -9.8% | -21.1% | -27.7% | -7.9% | -22.1% | -22.4% | -22.3% | -75.9% | -79.5% | -74.7% | -43.2% | -14.5% | |
| Balance Sheet & Debt | ||||||||||||||||||||||||||||||||||||||||
| -330 | -297 | -416 | -382 | -419 | -381 | -393 | -451 | -418 | -426 | -384 | -393 | -385 | -371 | -347 | -329 | -309 | -290 | -337 | -394 | -594 | -573 | -537 | -502 | -489 | -704 | -681 | -656 | -669 | -618 | -544 | -562 | -517 | -469 | -415 | -369 | -328 | -305 | -327 | -285 | |
| – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | -7.8 | -7.8 | -7.6 | -196.8 | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | |
| 83.6% | 79.4% | 85.3% | 84.1% | 83.0% | 82.0% | 67.5% | 63.2% | 64.7% | 64.8% | 67.9% | 65.5% | 64.1% | 65.1% | 63.9% | 61.9% | 58.9% | 55.3% | 61.8% | 66.0% | 77.5% | 76.5% | 75.5% | 74.1% | 73.0% | 82.1% | 81.9% | 80.7% | 82.6% | 80.6% | 80.6% | 90.1% | 89.8% | 89.0% | 88.4% | 81.3% | 83.7% | 85.8% | 89.3% | 94.8% | |
| 0.2 | 0.2 | 0.2 | 0.2 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.0 | 0.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Per Share | ||||||||||||||||||||||||||||||||||||||||
| -3.93 | -4.63 | -4.70 | -3.81 | -4.03 | -3.98 | -4.31 | -5.24 | -4.54 | -3.90 | -3.21 | -2.10 | -1.97 | -1.95 | -2.01 | -2.28 | -2.55 | -2.78 | -3.09 | -1.48 | 1.36 | 1.44 | 1.44 | -0.03 | -3.33 | -2.17 | -2.43 | -2.65 | -1.26 | -2.74 | -3.21 | -0.93 | -2.45 | -2.27 | -2.05 | -5.63 | -5.21 | -4.53 | -2.79 | -0.84 | |
| 0.03 | 0.03 | 0.03 | 0.72 | 0.72 | 0.72 | 0.71 | 0.02 | 0.02 | 0.02 | 0.02 | 0.02 | 0.02 | 0.02 | 0.02 | 0.02 | 0.02 | 0.02 | 0.02 | 1.28 | 3.90 | 4.30 | 4.32 | 3.05 | 0.11 | 1.00 | 1.05 | 1.08 | 2.43 | 1.70 | 1.66 | 3.95 | 2.48 | 2.51 | 2.56 | 0.19 | 0.22 | 0.18 | 1.07 | 1.05 | |
| 11.66 | 10.56 | 13.88 | 12.79 | 11.65 | 10.59 | 10.59 | 8.94 | 8.52 | 8.10 | 7.83 | 7.59 | 7.25 | 6.84 | 6.39 | 5.87 | 5.25 | 4.61 | 5.83 | 6.08 | 9.58 | 10.00 | 9.40 | 8.70 | 8.61 | 11.52 | 11.57 | 10.95 | 10.64 | 10.46 | 9.35 | 10.57 | 9.93 | 9.05 | 8.13 | 6.03 | 5.48 | 5.21 | 5.78 | 5.50 | |
| -3.30 | -3.87 | -4.16 | -4.12 | -3.55 | -3.51 | -3.26 | -0.80 | -1.19 | -0.75 | -0.40 | -2.16 | -1.54 | -1.34 | -1.48 | -1.65 | -1.90 | -2.02 | -2.26 | -0.75 | 1.87 | 1.97 | 1.89 | 0.35 | -2.70 | -2.02 | -2.27 | -2.44 | -1.54 | -2.55 | -3.02 | -1.83 | -2.88 | -2.79 | -2.43 | -3.58 | -3.50 | -3.04 | -1.51 | -1.16 | |
Showing the most recent 40 periods — older statements are on file for this stock.
Data as of: October 9, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)
Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.