BlackRock Inc is adding bitcoin futures as an eligible investment to two funds, a company filing showed, in a move to bring the world of cryptocurrency to its clients. The world's largest asset manager said it could use bitcoin derivatives for its funds BlackRock Strategic Income Opportunities and BlackRock Global Allocation Fund Inc. The funds will invest only in cash-settled bitcoin futures traded on commodity exchanges registered with the Commodity Futures Trading Commission, the company said in a filing to the Securities and Exchange Commission on Wednesday.