** Shares of Australia's Magellan Financial MFG.AX rise 5.8% to A$11.18, their highest level since August 20, 2025
** Stock has added more than 32% so far this week, in contrast with the benchmark S&P/ASX 200's .AXJO 3.8% decline
** MFG set for best week since late-March 2008, if gains hold
** Co said on Monday it will acquire all issued shares of Barrenjoey Capital Partners that it does not currently own at an implied value of A$1.62 billion ($1.15 billion) for Barrenjoey as a whole
** YTD, stock is up 12%
(Reporting by Shruti Agarwal in Bengaluru)
((Shruti.Agarwal@thomsonreuters.com))