Recently, there was a gym rework. One of the new features is that you obtain gym badges by participating in different activities related to individual gyms.
It is known that you can get Bronze, Silver and Gold gym badges (Source: Personal Experience), but I am wondering if there are any more tiers after Gold? If so, what is the amount of Badge XP required? It could possibly be something like 100 * 5 ^ ( x - 1 ) for tier x , where x_1 is bronze. Am I correct?