ERII vs PRTA

Comparison between Energy Recovery Inc (ERII, Company) and Prothena Corporation plc (PRTA, Company).

ERII is from the Industrials sector, while PRTA is from the Healthcare sector.

5-Year PerformanceERII has outperformed PRTA, delivering a return of -16.2% compared to -30.0%

ERII vs PRTA - Performance Comparison

Log

Key Characteristics

Financial metrics and valuation ratios

Metric	ERII(COMPANY)	PRTA(COMPANY)
Market Cap	$449M	$447M
Max Drawdown	83.98%	94.19%
Sharpe Ratio	-0.55	0.85
5Y Beta	1.01	0.89
Industry	Pollution & Treatment Controls	Biotechnology
P/E Ratio	-28.36	-3.01
Forward P/E	123.46	10.63
PEG Ratio	3.33	-0.08
5Y EPS CAGR	N/A	-1.54%
Debt to Equity	0.00%	0.00%
Free Cash Flow Yield	6.05%	-18.18%
P/S Ratio	3.25	7.62
P/B Ratio	2.42	1.45

Market Cap

Winner

ERII

$449M

PRTA

$447M

Max Drawdown

Winner

ERII

83.98%

PRTA

94.19%

Sharpe Ratio

ERII

-0.55

Winner

PRTA

0.85

5Y Beta

ERII

1.01

Winner

PRTA

0.89

Industry

ERII

Pollution & Treatment Controls

PRTA

Biotechnology

P/E Ratio

Winner

ERII

-28.36

PRTA

-3.01

Forward P/E

ERII

123.46

Winner

PRTA

10.63

PEG Ratio

ERII

3.33

Winner

PRTA

-0.08

5Y EPS CAGR

ERII

N/A

PRTA

-1.54%

Debt to Equity

ERII

0.00%

PRTA

0.00%

Free Cash Flow Yield

Winner

ERII

6.05%

PRTA

-18.18%

P/S Ratio

Winner

ERII

3.25

PRTA

7.62

P/B Ratio

ERII

2.42

Winner

PRTA

1.45

ERII vs PRTA - Historical Returns

Returns include dividend reinvestment.

Period	ERII	PRTA
1 month	-3.15%	-4.37%
3 months	-16.88%	-17.99%
6 months	-40.20%	-9.61%
1 year	-36.38%	+39.11%
5 years(CAGR)	-16.15%	-29.96%
10 years(CAGR)	-1.66%	-16.54%
Max(CAGR)	-0.73%	+1.45%

Winner

ERII

-3.15%

PRTA

-4.37%

Winner

ERII

-16.88%

PRTA

-17.99%

ERII

-40.20%

Winner

PRTA

-9.61%

ERII

-36.38%

Winner

PRTA

+39.11%

5Y(CAGR)

Winner

ERII

-16.15%

PRTA

-29.96%

10Y(CAGR)

Winner

ERII

-1.66%

PRTA

-16.54%

Max(CAGR)

ERII

-0.73%

Winner

PRTA

+1.45%

ERII vs PRTA - Annual Returns (2008 - 2026)

Returns include dividend reinvestment.

Year	ERII	PRTA
2026	-37.17%	-4.89%
2025	-9.40%	-30.14%
2024	-22.14%	-64.06%
2023	-8.63%	-32.07%
2022	-4.70%	+22.41%
2021	+56.29%	+301.63%
2020	+40.04%	-23.16%
2019	+42.50%	+50.76%
2018	-24.64%	-72.75%
2017	-18.76%	-24.70%
2016	+50.00%	-20.94%
2015	+35.70%	+234.69%
2014	-1.86%	-26.12%
2013	+62.28%	+278.86%
2012	+29.28%	+1.81%
2011	-37.83%	N/A
2010	-49.17%	N/A
2009	-13.46%	N/A
2008	-22.89%	N/A

ERII vs PRTA Drawdown Comparison

The maximum drawdown for ERII was -83.98%, occurring on Apr 12, 2012. Recovery took 1951 trading sessions.

The maximum drawdown for PRTA was -94.19%, occurring on May 27, 2025. This drawdown has not yet recovered.

The current ERII drawdown is -71.84%. The current PRTA drawdown is -88.91%.

Rank	ERII	PRTA
#1	-83.98% Jul 21, 2008 - Apr 20, 2016	-94.19% Sep 23, 2021 - May 27, 2025
#2	-74.13% Jul 18, 2023 - Jun 10, 2026	-90.85% Nov 27, 2015 - Sep 10, 2021
#3	-62.20% Sep 27, 2016 - Feb 24, 2021	-64.27% Mar 20, 2014 - Jun 17, 2015
#4	-37.96% Apr 21, 2016 - Aug 8, 2016	-36.96% Jul 28, 2015 - Nov 18, 2015
#5	-30.11% Nov 1, 2022 - Jun 6, 2023	-20.33% Dec 31, 2012 - Apr 9, 2013
#6	-29.03% Nov 19, 2021 - Sep 7, 2022	-18.45% Jun 20, 2013 - Jul 12, 2013
#7	-23.34% Apr 26, 2021 - Jun 29, 2021	-17.61% Jan 30, 2014 - Feb 25, 2014
#8	-21.18% Sep 9, 2022 - Nov 1, 2022	-15.12% Dec 16, 2013 - Jan 29, 2014
#9	-18.39% Jun 30, 2021 - Sep 3, 2021	-14.72% Oct 2, 2013 - Oct 25, 2013
#10	-18.15% Sep 3, 2021 - Nov 18, 2021	-11.68% May 28, 2013 - Jun 7, 2013
#11	-11.06% Mar 1, 2021 - Mar 11, 2021	-10.76% Aug 2, 2013 - Aug 22, 2013
#12	-8.91% Mar 15, 2021 - Apr 21, 2021	-10.14% Jun 22, 2015 - Jul 14, 2015
#13	-8.63% Sep 8, 2016 - Sep 15, 2016	-7.65% Mar 12, 2014 - Mar 19, 2014
#14	-7.01% Aug 11, 2016 - Sep 7, 2016	-6.94% Aug 29, 2013 - Oct 2, 2013
#15	-6.64% Sep 21, 2016 - Sep 27, 2016	-6.73% Jul 22, 2015 - Jul 28, 2015