ATHE vs PRTA

For growth investors, Alterity Therapeutics Limited (ATHE) is the stronger pick with 35.

3% revenue growth year-over-year, versus -92. 8% for Prothena Corporation plc (PRTA). Analysts rate Prothena Corporation plc (PRTA) a "Buy" — based on 28 analyst ratings — the highest consensus in this comparison. The "better buy" depends entirely on your goals: growth investors should weight revenue trajectory, value investors should weight P/E and PEG, and income investors should weight dividend yield and streak.

Over the past 5 years, Prothena Corporation plc (PRTA) delivered a total return of -57.

2%, compared to -64. 4% for Alterity Therapeutics Limited (ATHE). Over 10 years, the gap is even starker: PRTA returned -73. 0% versus ATHE's -87. 2%. Past returns do not guarantee future results, and the stock with the higher historical return may already have its best growth priced in.

By beta (market sensitivity over 5 years), Prothena Corporation plc (PRTA) is the lower-risk stock at 0.

96β versus Alterity Therapeutics Limited's 1. 04β — meaning ATHE is approximately 8% more volatile than PRTA relative to the S&P 500. On balance sheet safety, Alterity Therapeutics Limited (ATHE) carries a lower debt/equity ratio of 0% versus 5% for Prothena Corporation plc — giving it more financial flexibility in a downturn.

By revenue growth (latest reported year), Alterity Therapeutics Limited (ATHE) is pulling ahead at 35.

3% versus -92. 8% for Prothena Corporation plc (PRTA). On earnings-per-share growth, the picture is similar: Alterity Therapeutics Limited grew EPS 63. 5% year-over-year, compared to -99. 6% for Prothena Corporation plc. Over a 3-year CAGR, ATHE leads at 2. 0% annualised revenue growth. Higher growth typically commands a higher valuation multiple — check whether the premium P/E or P/S is justified by the growth rate using the PEG ratio.

Alterity Therapeutics Limited (ATHE) is the more profitable company, earning -223.

4% net margin versus -25. 2% for Prothena Corporation plc — meaning it keeps -223. 4% of every revenue dollar as bottom-line profit. Operating margin tells a similar story: ATHE leads at -268. 0% versus -1905. 8% for PRTA. At the gross margin level — before operating expenses — ATHE leads at 97. 7%, reflecting greater pricing power or product mix advantage. Stronger margins indicate durable pricing power, lower cost of revenue, or higher mix of software/services. They are one of the clearest signs of business quality.

None of the stocks in this comparison currently pay a material dividend.

All are effectively zero-yield and should be held for capital appreciation rather than income.

For long-horizon retirement investors, Prothena Corporation plc (PRTA) is the stronger choice — it scores higher on the combination of lower volatility, dividend reliability, and long-term compounding (low volatility (β 0.

96)). Both have compounded well over 10 years (PRTA: -73. 0%, ATHE: -87. 2%), confirming both are viable long-term holds — but the lower-volatility option typically results in less emotional selling during corrections. Retirement portfolios generally favour predictability over maximum returns. Consult a financial advisor before making allocation decisions.

Both stocks operate in the Healthcare sector, making this a peer-level intra-sector comparison — the same macro tailwinds and headwinds will affect both.

In terms of investment character: ATHE is a small-cap high-growth stock; PRTA is a small-cap quality compounder stock. These fundamental differences mean investors should not choose between them on a single metric — the "better stock" depends entirely on which of these characteristics aligns with your investment strategy.