Before CFD's were invented, what sort of leveraged products were out there?

It seems the CFD's were introduced to retail traders arounde 1990 and they have now become very popular, but its no secret that even before CFDs there were leveraged products used by financial firms, hedge funds, retail traders and so on.

therefore, before CFD's were invented, what sort of leveraged products were out there?

Any clue?

Thank you for your replies!