Hedge fund activism gained momentum in February, with the number of campaigns increasing by more than 25%, and March could prove to be another interesting month for the strategy after Elliott Advisors announced it would take on Alliance Trust.

The busy start to the year follows a strong 2014, when there were 344 campaigns initiated by activist investors, according to data compiled by Activist Insight. The number has more than doubled since 2011, when there were only 155.