Vanguard Holdings, a Pennysylvania-based investment company has become the largest shareholder of Twitter after acquiring a 10.3 per cent stake in the company, according to a regulatory filing. The company now owns 82.4 million shares of Twitter. Notably, on April 4, Elon Musk acquired a 9.2 per cent stake in the microblogging site, thus becoming the largest shareholder of the company.