A UK-based pension fund has invested 3% of its total assets in Bitcoin, becoming the first in the country to do so.The pension advisory firm Cartwright guided the unnamed fund in making the investment, with the private key divided between five institutions.The investment was driven by Bitcoin's long-term returns and its suitability for the pension fund's 10-year investment horizon.Cartwright expects institutional adoption of Bitcoin to follow a similar trajectory as pension schemes investing in equities in the 1970s.