HarborOne Bancorp, Inc. is a mid-tier stock holding company. The Company's principal subsidiary is HarborOne Bank (the Bank), a state chartered co-operative bank whose primary subsidiary is a residential mortgage company, Merrimack Mortgage Company, LLC (Merrimack Mortgage). The Company operates through two segments: HarborOne Bank and Merrimack Mortgage. The Bank segment provides consumer and business banking products and services to customers. Consumer products include loan and deposit products, and business banking products include loans for working capital, inventory and general corporate use, commercial real estate construction loans and deposit accounts. The Merrimack Mortgage segment consists of originating residential mortgage loans primarily for sale in the secondary market. The Company's subsidiary, Legion Parkway Company LLC, is a security company.