SPXU - The Burden Of The Bullish-Bearish Meme: Unleash The Total Power Of Compounding And Large Numbers Laws Instead
These are the primary sources of the US financial system's liquidity: The Fed's balance sheet, bank reserves (excess and required), treasury cash balances, and commercial bank loans.
Some definitions:
Fed's Balance Sheet - The Fed's balance sheet is a weekly report presenting a consolidated balance sheet for all 12 reserve banks that lists factors supplying reserves into the banking system and factors absorbing reserves from the system. The report is officially named Factors Affecting Reserve Balances, otherwise known as the "H.4.1" report.
Bank Reserves (Excess and Required) - bank reserves for commercial banks are held