And so that is often referred to as Base Money and in the US (and other countries), it's often the same thing as M0... (there are slight differences from country to country) and in this example, as soon as they printed and put it into circulation... (that was $4) we had $4 of base money... and that's obvious because as soon as they printed this and bought the security with it and it was in circulation, that $4 could be used to buy things, it could be used to facilitate transactions.