Prothena Corporation plc

PRTANASDAQHealthcare● Active

$8.56

$-0.23(-2.62%)

Market Cap$448143709

P/E Ratio—

52W High$11.8

52W Low$4.76

Avg Volume521K

Open$8.80

Beta-0.32

Free Cash Flow Financials Revenue

Prothena Corporation plc (PRTA) Free Cash Flow & Analysis

Annual & trailing free cash flow, FCF margin, YoY change, valuation ratios, and peer context.

PRTA · free cash flow · updated Jun 8, 2026

Core FCF metrics

PRTA · FCF · TTM · margin & CAGR

Free cash flow was −$163.7M for FY2025 (fiscal year ending 2025-12-31), down 8.9% year-over-year

FY2025 Free Cash Flow−$163.7M▼ -8.9% YoY

Trailing 12M (TTM)−$81.4Mtrailing 4 quarters sum

FCF Margin< −999%−$163.7M ÷ revenue

3-Year CAGRN/AN/A — contains negative FCF

5-Year CAGRN/AN/A — contains negative FCF

FormulaFCF = Operating Cash Flow − Capital ExpendituresTTM = trailing 4 quarters sumCAGR → N/A if either endpoint ≤ 0

Source: FMP /cash-flow-statement · SEC 10-K / 10-Q · USDUpdated: Jun 8, 2026

Annual free cash flow history

FCF ($B, upper) · YoY Growth % (lower)

Positive FCFNegative FCF

Free Cash Flow

YoY Growth %

Annual free cash flow data

PRTA · free cash flow history · annual / quarterly

Fiscal YearOperating CFCapExFree Cash FlowYoY ChangeFCF Margin

FY2025Latest−$163.6M(0M)−$163.7M▼ 8.9%—

FY2024−$150.1M(0M)−$150.3M▼ 10.0%-111.2%

FY2023−$133.9M(3M)−$136.7M▼ 25.1%-149.6%

FY2022−$108.8M(0M)−$109.3M▼ 218.7%-202.7%

FY2021$92.6M(1M)$92.0M▲ +214.2%45.9%

FCF = Operating Cash Flow − Capital Expenditures · CapEx shown as (negative) · Source: SEC filings via FMP

FCF valuation metrics

PRTA · P/FCF · FCF yield · FCF per share

Prothena Corporation plc (PRTA) reported negative free cash flow of −$0.16B. FCF-based valuation ratios are not meaningful when FCF is negative.

FCF Yield (TTM)

N/A

Free Cash Flow ÷ Market Cap

per FMP freeCashFlowYieldTTM definition

FCF per Share (TTM)

N/A

TTM FCF ÷ Shares Outstanding

Price / FCF

N/A

Share Price ÷ FCF per Share

EV / FCF (TTM)

N/A

Enterprise Value basis

FCF-based valuation ratios are only meaningful when free cash flow is positive. Negative FCF indicates capital expenditures exceeded operating cash flow.

Source: FMP /key-metrics-ttm · /cash-flow-statement Q · /income-statementFY2025 · 2025-12-31

Cash flow statement summary

PRTA · cash flow statement · operating / investing / financing

For FY2025, Prothena Corporation plc generated −$163.6M in operating cash flow and spent 0M in capital expenditures, yielding −$163.7M in free cash flow.

Operating Activities

−$163.6M

Cash from core business operations

2025-12-31

Investing Activities

−$0.1M

CapEx, acquisitions & investments

2025-12-31

Financing Activities

−$0.1M

Buybacks, dividends & debt

2025-12-31

FCF FormulaOperating CF (−$163.6M) − |CapEx| (0M) = FCF (−$163.7M)

For the complete Operating / Investing / Financing line-item breakdown:

View Full Cash Flow Statement →

Free cash flow vs peers (Healthcare)

PRTA vs peers · FCF

#CompanyFree Cash FlowYoYFCF MarginRelative

Prothena Corporation plcYOU

PRTA

−$163.7M-8.9%-1690.6%

Loss

UnitedHealth Group Incorporated

UNH

$16.07B-22.4%3.6%

82%

Eli Lilly and Company

LLY

$8.97B+2065.6%13.8%

46%

Healthcare · Sorted by FCF · FMP /cash-flow-statementFull FCF Rankings →

About Free Cash Flow & Methodology

Prothena Corporation plc (PRTA) reported free cash flow of −$163.7M for FY2025 (fiscal year ending 2025-12-31), down 8.9% year-over-year.

Based on available data, Prothena Corporation plc has maintained positive free cash flow for at least 1 fiscal year(s). FCF peaked at $92.0M in FY2021.

Data sourced from FMP /cash-flow-statement · SEC 10-K / 10-Q · USD.

Q&A and summaries align with SEC 10-K/10-Q cash flow disclosures and FMP /cash-flow-statement where noted.

Revenue Financial statements Net income Earnings Forecast Price history Market cap Cash on hand P/E ratio

Frequently asked questions

PRTA free cash flow · 8 questions

Prothena Corporation plc free cash flow was −$163.7M for FY2025, down 8.9% year-over-year. On a trailing twelve-month (TTM) basis, free cash flow stands at −$81.4M.

PRTA free cash flowPRTA FCFPRTA FCF 2025PRTA free cash flow TTM

▸ Source: FMP /cash-flow-statement · US GAAP · Prothena Corporation plc · Prothena Corporation plc SEC 10-K & 10-Q filings · US GAAP · Last updated: Jun 8, 2026