The Boston-based investment firm, which collectively owned 3.88 million Allergan shares through several of its funds as of end-June, had added roughly 2 million shares by the end of August, according to Thomson Reuters data based on Fidelity's monthly filings. The additions would likely make Fidelity the No.8 shareholder in Allergan, according to Thomson Reuters data, assuming there was no significant changing of hands in the company's top-10 shareholder base.