> I've made many thousands of orders that extend out to 5 or more decimal places.

The point wasn't that a trade containing that number happened to pop up. It was that the specific number 13076.389 was in the top 50 traded amounts on the exchange.

You'd expect there to be on average the same number of trades for 13076.388 and 13076.390 as there were for 13076.389, but that's not what the numbers show. Unless there is something special about the number 13076.389.