Like say there's an Ace trainer that gives you $1,000. Amulet Coin doubles to $2,000. Could it double to $4,000 to $8,000?
No, they do NOT stack.
Sources:
How to change your username How to add a user avatar Why was my post hidden? Question etiquette Flags vs Downvotes Anime FAQ Official PokemonDb League
Type a Pokemon name, type, move or ability to see instant results.