Not sure if you are asking who pays people bitcoins or who produces bitcoins. The latter is a stupid one if you are implying that. Bitcoins are mined, so if you want to get your hands on bitcoins without relying on anyone else then go mine bitcoins yourself.
He asking who is the supplier. Bitcoin is like the same as gold. It mined to have it and to grow your bitcoin. No one could never know who can supply the bitcoin. It is very confidential to know. It so wonderful that we have special tools to mine like the ordinary miners. Technology life goes through a good and better life.
Yeah exactly the bitcoin is mined like a gold is mined but the techniques of both of them are different. The mining of the bitcoin is purely technological and virtual while the gold having a physical existence and need you to work harder for it.
As we all know that bitcoin is a soft component so its mining is done through electronic machines and then the mined coins are supplied to the market for trade.