** Shares of Holista CollTech Ltd HCT.AX rise as much as 21.9% to A$0.089, their highest level since December 11, 2020

** Biotech firm records second-quarter group sales of A$1.2 million ($782,760.00) vs A$0.9 million a year earlier

** Stock set for best day since May 13, if current gains hold

** More than 988,000 shares change hands, over 4x the 30-day average volume of about 236,738

** YTD, stock has risen more than six-fold in value

($1 = 1.5330 Australian dollars)

(Reporting by Shruti Agarwal in Bengaluru)

((Shruti.Agarwal@thomsonreuters.com))