Investment behemoth BlackRock (BLK) dips a little toe into the cryptocurrency waters with a $360,457 investment in CME bitcoin futures earlier this year, according to an SEC filing.That accounts for 0.0014% of the its BlackRock Global Allocation Fund as of Jan. 31.It's not clear if the company still holds any bitcoin futures contracts, as the first batch were set to expire on March 26.And while it's a sliver of BLK's assets, it shows that huge investment firms are looking at the cryptocurrency.