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ISE Clean Edge Water Index (HHO)

HHO Index Logo

The ISE Clean Edge Water Index (HHO) is a modified market capitalization-weighted index designed to track the performance of companies that derive a substantial portion of their revenues from the potable water and wastewater industry, as determined by Clean Edge. Industry exposure includes water distribution, infrastructure (pumps, pipes, and valves), water solutions (purification and filtration), and ancillary services such as consulting, construction, and metering.

An  exchange traded fund, FIW , is based on the ISE Clean Edge Water Index and is sponsored by First Trust Advisors L.P. See index components and learn more about our methodologies, up-to-date performance, and licensed products below.

facts Click above to access the ISE Clean Edge Water Index (HHO) Fact Sheet.

ISE Clean Edge Water Index Components (Last updated March 2024)

WMSAdvanced Drainage Systems Inc
AAgilent Technologies Inc
AQNAlgonquin Power & Utilities Corp
AWRAmerican States Water Co
AWKAmerican Water Works Company Inc
BMIBadger Meter Inc
CWTCalifornia Water Service Group
SBSCompanhia de Saneamento Basico
CNMCore & Main, Inc.
ECLEcolab Inc
WTRGEssential Utilities, Inc
FERGFerguson Plc 
FLSFlowserve Corp
FELEFranklin Electric Co
HWKNHawkins, Inc.
IEXIDEX Corporation
IDXXIDEXX Laboratories Inc
ITRIItron Inc
LNNLindsay Corporation
MEGMontrose Environmental Group, Inc.
MLIMueller Industries Inc
MWAMueller Water Products Inc
PRMWPrimo Water Corp
ROPRoper Technologies Inc
STNStantec, Inc.
TTEKTetra Tech, Inc.
VLTOVeralto Corp
VMIValmont Industries Inc
WATWaters Corp.
WTSWatts Water Technologies Inc
XYLXylem Inc
ZWSZurn Water Solutions Corp

constituents Click above to access an overview of all HHO Index constituents.

ISE Clean Edge Water Index Semi-Annual Changes

As a result of the March 2024 evaluation and/or intraquarterly changes, the following securities were most recently added or removed from the index: 

Additions: Hawkins, Inc. (Nasdaq: HWKN), Montrose Environmental Group, Inc. (New York: MEG), and Veralto Corp. (New York: VLTO)

Deletions: Danaher Corp. (New York: DHR), Energy Recovery, Inc. (Nasdaq: ERII), and Middlesex Water Co. (Nasdaq: MSEX)

Historical changes are available here .

ISE Clean Edge Water Index Performance

Historical index performance is available here .

ISE Clean Edge Water Index Methodologies

Index Calculation

The ISE Clean Edge Water Index (HHO) (formally the ISE Water Index) began on December 29, 2000 at a base value of 28.80.  Click here  to learn more.


Eligible security types generally include common stocks, ordinary shares, and depositary receipts. 

Eligibility Criteria

To be eligible for inclusion in the Index, a security must meet the following criteria (see complete list of index screens by clicking on the Methodology link below):

  • the issuer of the security must derive a substantial portion of their revenues from the potable and wastewater industry, according to Clean Edge;
  • be listed on The Nasdaq Stock Market, the New York Stock Exchange, NYSE American, or the CBOE Exchange; 
  • a minimum worldwide market capitalization of $100 million;
  • a minimum free float of 20%;
  • a minimum three-month average daily dollar trading volume (ADDTV) of $500 thousand;
  • one security per issuer is permitted;
  • have “seasoned” for at least three months on an index recognized market;
  • the issuer of the security may not have entered into a definitive agreement or other arrangement which would likely result in the security no longer being Index eligible; 
  • may not be issued by an issuer currently in bankruptcy proceedings.

methodology Click above to access detailed HHO index methodology information.

Financial Products Based on the ISE Clean Edge Water Index

The First Trust Water ETF (FIW) is based on the ISE Clean Edge  Water Index (HHO) and is sponsored by First Trust Advisors L.P.

Nasdaq® is a registered trademark of Nasdaq, Inc. and Clean Edge® is a registered trademark of Clean Edge, Inc. The information contained above is provided for informational and educational purposes only, and nothing contained herein should be construed as investment advice, either on behalf of a particular security or an overall investment strategy. Neither Nasdaq, Inc. nor Clean Edge, Inc. nor any of its affiliates makes any recommendation to buy or sell any security or any representation about the financial condition of any company. Statements regarding Nasdaq-listed or other publicly listed companies or Nasdaq Clean Edge proprietary indexes are not guarantees of future performance. Actual results may differ materially from those expressed or implied. Past performance is not indicative of future results. Investors should undertake their own due diligence and carefully evaluate companies before investing.  ADVICE FROM A SECURITIES PROFESSIONAL IS STRONGLY ADVISED.