M&A stands for mergers and acquisitions. Mergers are when two companies join together to become whole, so the sum of the two is larger than the two separate initial parts. An acquisition is when one company completely buys out the other and absorbs all its functions. Investment banks make money from mergers and acquisitions because that brings in more clients and therefore more income to the banks. This merging will also help the companies that are merging as they will benefit from the reputation of the bank they are merging with.