The huge boom in blank-check companies powered the best first quarter for mergers and acquisitions since 1980, as investors flush with cash looked for new opportunities along with the reopening of economies after the coronavirus pandemic. There was $1.3 trillion of global M&A activity in the first quarter of the year, data provider Refinitiv said, surpassing even the strongest first quarter of the dotcom bubble in 2000, when dealmaking surged to $1.2 trillion.