Neither: Correct is: STORED The old man had all his money STORED in a small box under the bed.

thanks a lot.

You can use 'to store' ,referring to the reason for keeping the money under the bed. You can also use 'stored' here to indicate the state in which the money is kept , it is stored.

The old man had all his money in a small box under the bed. It makes sense, that's why!