it looks to be some sort of a ....stock.... or possible a bank deposit

it reads, on the 1 march 1928 the holder of this "paper" made an amount of 1 billion german marks ( the currency at the time )

the text is kind of small and it hurts my eyes to read up so close to the screen

it could be worth something, not really sure. it might have some sort of historical significance

they could be bank deposits after hyper inflation kicked in, the notes at the top seem to indicate some sort of a deposit