The 2014 market for mergers and acquisitions was, in motoring terms, the equivalent of a traffic-free motorway interrupted by the odd Ferrari or McLaren. The early stages of 2015 in contrast have seen the roads filling out with five-door family sedans and mid-range saloons.

Activity in 2014 was fuelled by occasional mega-deals - a flashy $50 billion industrial merger or a $100 billion transatlantic takeover.