Australia's Sequoia Financial Group dives on regulator's probe

** Sequoia Financial Group SEQ dives as much as 28.1% to A$0.23, lowest since July 30, 2020

** Financial services co says Australian corporate regulator ASIC has began investigation into suspected contraventions of the Corporations Act & ASIC Act 2001 by its unit

** Stock sees busiest session since December 30, with 699,787 shares traded

** SEQ last down 6.3%, taking YTD losses to 22.1%