WWI of course, juiced the economy with war production. There was a mini recession post-war, and a flu pandemic, but by the 1920s the newly 1913 minted Federal Reserve loosened interest rates and that spawned the roaring 20s and the flapper era. In 1928 the Fed raised interest rates. By the time of the October 1929 crash, they had raised interest rates 5% or thereabouts.
The Greenspan housing bubble was hatched with "extraordinary, extraordinary, extraordinary" low rates, to use Greenspan's term. These were in response to the 2001 Bursting of the Tech Bubble. Wow did it crash, so many names. Lucent, Enron, Worldcom, Kmart (the first time). Venture capital had bet many farms on loose money and internet startups run by freshly minted MBAs who had never seen a downturn. Driving blind with no instruments. How does that usually work out?
By 2008 the Housing bubble was under duress. Super safe USA mortgage pools were sold worldwide. Only thing was they weren't safe. So we had the Great Recession, ZIRP (zero interest rate policy), QE1, followed by more QE's under different names but they were all the same: inject liquidity into the banking system to keep everyone from 1929, 1972, or 2008 all over again.
The Republicans in Congress made sure the Republicans got paid with tax cuts. Bank that money in assets, live off the business, and keep complaining. Powell followed the money with Trump. Come Covid,let's do ZIRP again and inject money into the system. Give it all to the top, and SNAP to the bottom, and Stim checks to everyone. No one ever banked on a rainy day anyway. The result was inflation and Powell has had to raise interest rates fast.
So the purpose of this tale is to note that, like the 1920s, we've had a long period of loose money, crashes, more loose money, looser money, the loosest money, Brink's truck money .... an now it's 23 years later and the Fed, just like 1929, has raised interest rates faster than you can count - 5% all over again. Which is why some economists are insisting recession or perhaps Depression is nigh.
Buy PayPal!