How to make 2 side by side columns look distinct from each other?

I have a price chart like below. The 'buy price' is a listing on its own.. and 'sell price' is a listing on its own too. It just happens that they are placed side by side. E.g. The buy price is not related to the sell price in the same row.

My problem is how do I make it distinct that they are separate columns that are not directly related? But at the same time, they need to be both seen at one glance by the user for comparison/reference.

I was thinking of putting each of them in their own tabs but as per client requirement, that isn't an option.

Do note that this is going to be on a mobile device so I don't have much horizontal space to play around with.