“When Plaid announced its $250 million Series C investment last year, it left out a couple of key investors. Today it revealed that Mastercard and Visa quietly participated in the round. For a company like Plaid, which builds APIs to enable customers to access their bank accounts inside applications in a seamless way, having the blessing of two of the major credit companies in the world is a big deal. It could signal that the startup intends to move more broadly into payments, although it didn’t make any specific assertion it was doing that in the announcement.”