** Shares of One Click Group tumble as much as 23.1% to A$0.010, their biggest pct loss since Aug. 1

** Fintech platform gets commitments for a sale of 401 mln shares at A$0.0081 each, a 37.7% discount to last close

** Sale to raise A$3.25 mln ($2.17 mln) to be used for marketing and other purposes

** Around 8.4 mln shares traded, 18.3x the 30-day avg

** Stock flat YTD, including current session's moves

($1 = 1.4952 Australian dollars)

(Reporting by Kumar Tanishk in Bengaluru)

((Tanishk.Kumar@thomsonreuters.com;))