Constellation Software Tumbles as ‘Irreplaceable’ Founder Resigns

Mark Leonard resigned as president of Canada’s Constellation Software Inc. for health reasons, sending the shares to their lowest level in more than a year and prompting an analyst downgrade.

Constellation shares fell 5.5% to C$3,910.71 as of 11:40 a.m. in Toronto, erasing C$4.8 billion ($3.4 billion) in market capitalization for the Toronto-based company. The stock had briefly plunged 19%.