The U.S. economy as quantified by GDP has been sputtering along in slow growth mode for a number of years. It took a huge hit in 2020 due to covid shutdowns and has not nearly recovered. But stock prices have been rocketing upwards, and this past year is no exception. Markets took a cliff-dive in March, but have since way overshot to the upside.
Here is a plot of the past five decades of U.S. GDP and of the Wilshire 5000 index, which approximates the total stock market capitalization in the U.S.:
These two curves have crisscrossed each other over the past five decades, but in recent years the stock market has roared to the upside. One of Warren Buffet’s favorite metrics as to whether stock are overvalued is to consider the ratio of these two quantities, i.e. the market-capitalization-to-GDP (Cap/GDP) ratio:
A balance sheet gives a snapshot of a corporation’s assets and liabilities. The difference between total assets and total liabilities is (by definition) the value of the equity owned by the owners or shareholders of the company.
With, say, a manufacturing firm, the assets would include tangible items such as buildings and equipment and inventory, and intangibles such as cash, bank accounts, and accounts receivable. Liabilities may include mortgages and other loans, and accounts payable such as taxes, wages, pensions, and bills for purchased goods.
The balance sheet for a bank is different. The “Assets” are mainly loans that the bank has made, plus some securities (such as US Treasury bonds) that the bank has purchased. These assets pay interest to the bank. The money the bank used to make these loans and purchase these securities came mainly from customer deposits or other borrowings by the bank (which are considered “Liabilities” of the bank), and also from paid-in capital from the bank owners/shareholders.  As usual, the current equity of the bank is assets minus liabilities. Thus:
The Federal Reserve System is a complex beast. We will not delve into all the components and moving parts, but just take a look at the overall balance sheet.
Unlike other banks, the Fed has the magical power of being able to create money out of thin air. Technically, what the Fed can do with that money is mainly make loans, i.e. buy interest-bearing securities such as government bonds. The Fed makes its transactions through affiliated banks, so it credits a bank’s reserve account with a million dollars, if it buys from that bank a million dollars’ worth of bonds. Those bonds then become part of the Fed’s “assets”, while the reserve account of the bank at the Fed (which is a liability of the Fed) becomes larger by a million dollars. Since the Fed is not a for-profit bank, the “Equity” entry on its balance sheet is nearly zero. Thus, total assets are essentially equal to total liabilities.
The Fed also has the power of literally printing money, in the form of Federal Reserve Notes (printed dollar bills). These, too, are classified as liabilities. Thus, you are probably carrying in your wallet right now some of the liabilities of the central bank of the United States.
Before 2008, the balance sheet of the Fed was under a trillion dollars. Nearly all the “Liabilities” were the Federal Reserve Notes and nearly all the “Assets” were US Treasury securities. The reserve accounts of the affiliated Depository Institutions was minuscule. All that changed with the Global Financial Crisis of 2008-2009. To help stabilize the financial system, the Fed started buying lots of various types of securities, including mortgage-backed securities (MBS) . The Fed thus propped up the value of these securities, and injected cash (liquidity) into the system.
Here is a plot of how the assets of the Fed ballooned in the wake of the GFC, from about $ 0.9 trillion to over $ 4 trillion:
The initial purchases in 2008 were US Treasuries, which the Fed had prior authorization to do. To buy other securities, especially the mortgage products, required congressional authorization. The increased liabilities of the Fed which offset these purchases were mainly in the form of larger reserve accounts of the affiliated banks. The Fed started paying interest on these reserve accounts, to keep short term interest rates above zero at all times (otherwise the whole money market in the U.S. might implode).
With the Fed relentlessly buying the mortgage and bond products, the interest rates on long-term mortgages and bonds was kept low. This was deemed good for economic growth. The Fed tried to sell off some securities to taper down its balance sheet in 2018, but that effort blew up in its face – – the stock market started crashing in response in late 2018, and so the Fed backtracked . You can look at weekly tables of the Fed balance sheet here.
Anyway, the GFC and its aftermath provided the precedent for massive purchases of “stuff” by the Fed. When the Covid shutdown of the economy hit in March of this year, the Fed very quickly went into high gear. Its balance sheet shot up from $4 trillion to $7 trillion in just a few months. It bought not only Treasuries and MBS, but corporate bonds. This was way outside the Fed’s original charter, but the crisis was so intense that nobody seemed to care whether these actions were legal or not. And now, to finance the huge deficit spending of the federal government in the wake of the shutdowns, the Fed has been buying up nearly the entire issuance of Treasury bonds and notes.
These actions may have long term consequences we will explore in later posts . For now, the Fed has made it clear that it will keep interests rates near zero for at least the next couple of years. Invest accordingly.
 Huge caveat: This statement gives the impression that a bank must first receive say a thousand dollar deposit before it can make a thousand dollar loan. That is not the case. The reality is just the opposite: the act of making a thousand dollar loan actually CREATES a corresponding thousand dollar deposit. This is very counterintuitive, and I won’t try to explain or justify this point here.
 Technically, the Fed is not “buying” the mortgage-backed security (MBS). Rather, it is making a “loan” to the bank, and holding the MBS as collateral against that loan.
 It is now harder to take the federal deficit seriously as a constraint on spending: the government can issue unlimited bonds to fund deficits, which the Fed will purchase to keep interest rates low. Yes, the government has to pay interest on those bonds, but the Fed has to return most of that interest to the Treasury, so the real cost to the government of that extra debt is low.
It is not straightforward to define what “money” is in a modern national economy. Simply tallying the amount of coins and paper currency is inadequate. Most buying and selling is now done by shifting numbers between abstract bank accounts, not by pushing a bundle of bills across a table. Thus, these bank accounts serve the functions of money (medium of exchange and store of value). The question then arises as to which of these financial accounts to regard as money.
Among financial assets, there is a broad spectrum of liquidity. Typically you can write a check on your checking account which, when it clears, provides immediate and final settlement for a purchase. On the other hand, if you want to tap your brokerage account with its holdings of Apple stock to buy a television, you would typically have to sell (liquidate) your stock. A third party would have to be willing to give you something more money-like (e.g. credit your money market fund at your brokerage) in exchange for the stock at some negotiated price. Then you might have to transfer the funds from your brokerage fund into your bank checking account before you can actually buy that TV. Because of all these intermediate steps, and the fluctuating value of the stock before you complete the sale, the stock holding would not be counted as “money”, even though its value enabled you to ultimately make your purchase.
There are a number of measures of money in modern economies. In the U.S. some of these are:
M0: The total of all physical currency (coins and paper bills).
MB (“Monetary Base”): The total of all physical currency (coins and bill) plus Federal Reserve Deposits (special deposits that only banks can have at the Fed). This is money essentially created by the government plus the Federal Reserve, which does not necessarily enter the private economy to be spent.
M1: Physical currency circulating outside of the Fed and private banking system, plus the amount of demand deposits, travelers’ checks and other checkable deposits. This is highly “liquid” money, i.e. accepted and used for transactions in the private economy.
M2: M1 + most savings accounts, money market accounts, retail money market mutual funds, and small denomination time deposits (certificates of deposit of under $100,000). The funds in these additional savings and money market accounts can in general be easily transferred to checkable accounts, and thus could go towards making purchases if desired.
MZM: “Money Zero Maturity” is one of the most popular aggregates in use by the Fed because its velocity has historically been the most accurate predictor of inflation. It is M2 – time deposits + institutional money market funds.
Below is a chart showing the growth in the U.S. in the past fifteen years of M0 (total currency, labeled “currency in circulation), MB, M1, and M2. The grayed areas are recessions, i.e. 2008-2009 and the present. 
The M1 money supply (green line) was about $1.4 trillion ( $1,400 billion on the chart) in 2005, was fairly steady for several years, then started a steady ramp up to $4 trillion by January, 2020. Due to the extraordinary events associated with the Covid-19 shutdown (government stimulus package plus Fed purchases of securities), M1 jumped up to $ 5.4 trillion by August of this year. M2 followed similar trends, though on a much larger scale, rising to$18.3 trillion this year. This compares to a current U. S. total GDP of about $21 trillion.
The lowest line on the chart is the physical currency (blue line), which has grown slowly but steadily. The “Total MB” (red) line, was essentially on top of the blue line up until the 2008-2009 recession. Since MB = physical currency plus reserves, this meant that the amount of money in the reserve balances at the Fed of the private banks was nearly zero before 2008. The reserves jumped up (difference between the red and blue lines) in 2009, with the onset of massive purchases of securities by the Fed (“quantitative easing”). The Fed buys these securities from the banks, and credits their reserve accounts. The Fed has tried to taper down its holdings in recent years (red line declining 2015-2019), but suddenly purchased trillions more this spring (red line jumping up in 2020). Most pundits hold that all this Fed money injected into the financial system has been the major cause of the enormous rise in stock prices in the past decade, especially in the past six months.
 Chart produced on the St. Louis Fed “FRED” site, https://fred.stlouisfed.org/categories/24 . This site has a wealth of economic data. Unfortunately, it is not easy to change units, so I was stuck with “billions” instead of “trillions” for the axis labels. Also, the M0 and MB numbers were only available in “millions”, so I had to divide those numbers by 1000 to get them to fit on the plot with M1 and M2. The grayed out spots on the graph labels is where I blotted out the “ /1000 ” which the plotting software put in. It would have been cleaner, in retrospect, to have exported the data to Excel and replotted it there.