The volume of online and mobile deals in 2015 increased 12% to 2,798 transactions from 2,493 in 2014, according to investment bank Berkery, Noyes & Co. Deal value rose 19% to $156.49 billion from $131.16 billion in 2014. Of the 10 largest transactions in 2015, five occurred in the fourth quarter. These five deals, with a combined value of $22.79 billion, accounted for 15% of the industry’s aggregate value, Berkery Noyes says.