** Shares of Regal Asian Investments RG8.AX fall as much as 3.8% to A$1.915, their lowest level since Dec 8, 2023
** Stock posts biggest intraday decline since Feb 20
** Investment manager devalues stake in biotech Opthea OPT.AX to A$0.20/shr vs OPT's last close of A$0.60 before trading was suspended
** OPT on Monday warned of insolvency after its late-stage trial for its wet age-related macular degeneration injection failed
** RG8 stock last down 2%, bringing YTD losses to 8.9%.
(Reporting by Aaditya Govind Rao in Bengaluru)
((Aaditya.govindrao@thomsonreuters.com;))