I was confused as well, so I checked various European languages for what their word for billion is. I suspect they are french, using an abbreviation for milliard, the French word for billion.

Not just French, also for example German and Polish.

Milion, Miliard, Bilion, Biliard = Million, Billion, Trillion, Quadrillion

(neither are justified because neither start at the beginning, that is at a thousand :) )

This is one of the places where the US has a better naming standard than us in the EU imo. Just feels much more intuitive to count up with Bi, Tri without doubling them up every time.

My guess is that the OP meant to say "5bn USD". I frequently see billion abbreviated to "bn" in UK newspapers such as the Financial Times.

Oops, fixed. I meant 5 billions (5e9), USD is indeed US Dollars.

probably billions. "md" would be "milliard" and "milliard" is french for billions.

Maybe milliard (billion)