Coin Swap Hex
From the Super Mario Wiki
The Coin Swap Hex is a type of Hex in Mario Party DS. The player who possesses it can choose to place it on any Blue Space or Red Space within five spaces from their current location. Then, if an opponent lands on it, all of their coins will be traded with the coins of the one who threw it. If the player or team who threw it lands on it, the hex will be canceled out, but they will receive 5 coins. The Coin Swap Hex can be owned by getting it in a Hex Area or steal it using the Snag Bag.