When an exchange works with an electronic order book and a matching engine, it usually tries to match orders in realtime during trading hours. That means when a new order comes in, it tries to match this order to existing ones as soon as possible, usually within microseconds.
Are there any exchanges which don't do this in realtime, but instead employ a timed interval, which gives the participants a certain time (e.g. some seconds) to decide about their orders and place them, and then matching all known orders after the interval has ended?
This would eliminate the advantage of hosting trading algorithms nearby to the exchange, thus eliminate the need for co-hosting and the rally to host closest, reducing the trading to what it should actually be, a decision based on publicly available information.