London–based Henderson Group is coming off of a stellar year, having grown capital by 24.5 percent in 2014 after an even more spectacular 2013, in which capital soared 56.7 percent. Henderson appeared on Alpha’s 2014 Europe Hedge Fund 50 ranking at No. 14. Assets soared following the firm’s acquisition of London’s Gartmore Investment Management in April 2011, which was key in strengthening Henderson as a leader in long-only and absolute return offerings. The following year, however, assets dropped by 25.9 percent to $5.27 billion as a result of Henderson’s exposure to Europe and equities in a volatile political and economic landscape. Henderson enjoyed a strong turnaround in 2013…