Exchanges compete on speed. If exchange A delivers data in half the packet size and requires smaller word sizes to operate on and exchange B decides it's okay t

Exchanges compete on speed. If exchange A delivers data in half the packet size and requires smaller word sizes to operate on and exchange B decides it's okay to double the packet size and requires twice the word size... exchange A gets the trade and exchange B is left holding the bag. Back in the day the major exchanges, NASDAQ and NYSE in the U.S. and the TSX in Canada used to operate as a mafia with a monopoly on the stock market. Entire exchanges came into being strictly on the basis that they had lower bandwidth requirements and operated faster, such as BATS and DirectEdge (which ended up merging), CHI-X, Omega, and a host of competition emerged to actually focus on technology. They ended up taking a large chunk of market share away from the major exchanges. Now NASDAQ and NYSE have since caught up, and in some ways they did so by buying out these competitors. Modulo some embarrassing glitches over the past few years, the major exchanges need to continue supporting their legacy systems for major institutions who are very slow and hesitant to upgrade any aspect of their technology. NASDAQ has a more advanced and modern data feed and that feed doesn't have this issue, BRK.A is being reported properly at its price as we speak, but that feed isn't widely adopted except by firms that generally build their own technology and have a team that can keep their tech up to date. The feed that has this issue is like 20 years old now and rarely gets updates, and many firms like to keep it that way.