stick (money) in (an account or investment)
If you put money into an account without thinking very much about it, you can say that you "stuck" your money into that account.
You can also "stick" money into investments like stocks or bonds.
While saying that you've "stuck" your money into an account suggests that you did it without much planning, this phrase is not too negative. Sometimes it's OK just to "stick" your money in a bank account or a fund.