In the midst of all the back and forth, Yahoo’s (NSDQ: YHOO) largest shareholder Capital World Investors has doubled its holdings in the company, according to an SEC filing today. As of March 31st this year, it had 10.1 percent stake, and owns 135,542,600 shares. That up 95 percent from its Yahoo holdings on Dec. 31, as News.com points out. Meanwhile, the second largest shareholder Legg Mason indicated its position earlier this week: it is prepared to support an independent Yahoo, should Microsoft (NSDQ: MSFT) lower its offer.