Prothena Corp Public (PRTA) Tax Rate (2012 - 2026)

Prothena Corp Public's Tax Rate history runs 15 years deep, the most recent figure standing at 0.0% for Q1 2026.

• On a quarterly basis, Tax Rate fell 192.0% year-over-year to 0.0% in Q1 2026; TTM through Mar 2026 was 41.57%, a 4631.0% decrease from a year earlier, with the FY2025 full-year figure at 21.54%, down 2668.0% from the prior year.
• Tax Rate eased to 0.0% in Q1 2026 per PRTA's latest filing, from 0.17% in the prior quarter.
• Across five years, Tax Rate topped out at 7.3% in Q2 2023 and bottomed at 89.81% in Q4 2022.
• The 5-year median for Tax Rate is 1.92% (2025), against an average of 7.3%.
• Across the five-year window, Tax Rate slumped 8967 bps in 2022 and jumped 9425 bps in 2023, its largest moves.
• Year by year, Tax Rate stood at 89.81% in 2022, then soared by 105 bps to 4.45% in 2023, then tumbled by 43 bps to 2.55% in 2024, then sank by 93 bps to 0.17% in 2025, then tumbled by 98 bps to 0.0% in 2026.
• Per Business Quant, the three latest PRTA Tax Rate figures stand at 0.0% (Q1 2026), 0.17% (Q4 2025), and 1.08% (Q3 2025).