There have always been movements with dissenting views on the money system: how it runs and whom it works for. But in the aftermath of the 2008 financial crisis, a new wave of money agitators has emerged, each with very distinct ideas about what money means. From bitcoin evangelists to advocates of modern monetary theory, they have divided into warring factions.

To understand them and what theyre fighting for, its important to understand the system theyre challenging.

Our money system is underpinned by national central banks and treasuries that issue foundational base money . This includes the physical cash in our wallets and also reserves, the special forms of digital money that commercial banks hold in their central bank accounts, which are inaccessible to us.

These commercial banks then boost the money supply by issuing a second layer of money on top of the central bank money layer, through a process called credit creation of money (sometimes called fractional reserve banking) to create commercial bank money, which we see as bank deposits in our bank accounts.

The details are subtle and complex especially at the international level but the interaction of these players issuing money and taking it out of circulation makes the money supply expand and contract as if it were breathing. Monetary reform groups target different elements of this. Here are five of them.

1. Government Money Warriors