Every single exchange market will have their own rate going
Not really. As soon as you see price differences between the markets you can make money with arbitrage: Buy cheap on one market, sell expensive on the other markets. So the people who do this balance the prices between the individual markets.
So even if your market closes during the night: If there are crashes on other major markets during this time people on your market will sell (or buy) as soon as your market opens again.
You're seeing price differences NOW. What are you talking about?