A question of size

There is an object on earth that behaves in a curious manner.

It gets bigger the more you take out of it and smaller the more you put into it.

What is it?

• Size does matter! Commented Oct 15, 2016 at 19:15
• Nice wordplay ! Commented Oct 15, 2016 at 19:22
• This is a well known puzzle, and it is very low quality anyway Commented Oct 15, 2016 at 20:09
• I know a variation of this riddle: "It doesn't weight anything, but it's able to let a ship sink" Commented Oct 17, 2016 at 8:04

It is a

hole.

As you remove material (like dirt for example) the hole gets larger; as you add material, it gets smaller.

• >! yeah, that was quick! @tmpearce. what has holes but still holds water? Commented Oct 15, 2016 at 19:38
• @NONAMEBRAND A sponge. Commented Oct 15, 2016 at 19:41
• Indeed, you've played knifey spoon before! @rand al'thor Commented Oct 15, 2016 at 19:44

Is it

Debt?
The more money you take out of an account that is in debt, the more you will owe. If you owe more money, than the debt is larger. Likewise, if you put more money into the account in debt, the smaller the debt will be.