<Page>

                                                                      Exhibit 21

                         Subsidiaries of the Registrant

                         ------------------------------

<Table>
<Caption>

                                                                       Percentage
                                                                       of Voting
                                                                       Securities
                                                       State of        Owned By
                                                     Incorporation     Registrant
                                                     -------------     ----------

                                                                      
    Compupower Corporation                              Delaware            100%

    Value Line Securities, Inc.                         New York            100%

    The Vanderbilt Advertising Agency, Inc.             New York            100%

    Value Line Publishing, Inc.                         New York            100%

    Value Line Distribution Center, Inc.                New Jersey          100%
</Table>







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