The massive Indian bull-run over the last few years has led to swelling assets under management (AUM) of mutual funds. In the four equity categories, AUM at the end of March 2007 were up by 21%  over the same period last year.  The fastest growth, albeit on a small base, happened to index funds.  From Rs219.61 crore in March 2006, assets managed by index funds shot up by 181% to Rs617.56...