Off Board Trade

When two private parties have something meaningful to trade - like... one seller is selling a large block of shares to a buyer, they may not want to tip their hand to the rest of the market that so much volume in transactions are going on. So they might file paperwork and create an off board trade, meaning that the trades they make will not be counted by the Big Board, the Little Board, or any other board, until it legally must be tallied for the public down the line.