The Piggy Bank is a feature that allows players to save up gems and exchange the same amount for: a percentage of extra gems; more coins; and a random item.
If you don't want to wait until it fills up, you can open your Piggy Bank whenever you want! In this case, you can pay a little less, but also win a little less.
If the Piggy Bank is completely filled, you'll have 24 hours to open it. Not doing this will cause the Piggy Bank to reset and the amount of gems you saved will be lost!
After paying for the withdrawal, the currencies and items will then be added to your total balance, and the Piggy Bank will start from scratch on the next level, with a higher capacity and more rewards for you!