These are some things that I have learned.
1. Do not follow or trust analyst advice when buying stocks. Leading into the 2008 financial crisis, Wall Street analysts (working for investment banks) were rating stocks & funds a "Buy," while betting against them (to go lower). They do not have to disclose their short positions to consumers.
2. Another stock market crisis, like 2008, will happen again. Derivatives are still unregulated. An unregulated derivative market was the root cause. The root cause still exists.
3. Trading on the stock market is not fair. We all do not have access to the same information. Stocks, commodities, & derivatives trade on information-Wall Street information. The government doesn't care. Bankers become regulators, regulators become bankers, bankers become members of the Federal Reserve and Ivy League college business professors (that sit on the banks' board of directors). They are all the same people.
4. The people that lost the most money (in 2008) were invested in pension plans. What do pension plans invest in? Some invest in derivatives of home loans known as CDOs or collateralized debt obligations. These are the things that caused the market collapse of 2008. AIG provided insurance on these things (but didn't set any money aside to pay) if the underlying loans if the CDOs defaulted (making them worthless). The insurance was called a Credit Default Swap or CDS (a derivative of the CDO). Since AIG couldn't pay and was taken over by the government, everyone that had a pension plan invested in CDOs lost EVERYTHING. I don't invest in pensions (401k plans).
5. This is how buying a house worked going into the financial crisis. A buyer (you or me) purchases a home from a lender (bank). The lender repackages a bunch of home loans, car loans, etc (people with credit rating from poor to great). This repackage instrument is called a CDO. The lender obtains a new credit rating for the CDO of AAA (the same as US treasury bonds). The credit raters (S&P, Moody's, or Fitch) trust the bank to tell them what's in the CDO & how to rate it; and they get paid more for giving AAA ratings instead of BBB ratings. Then, the lender sells the CDO to an investor (Fannie Mae, Freddie Mac). A speculator believes the CDO will default and they take out insurance in the form of a credit default swap (CDS)-another type of derivative, from AIG. If the loans in the CDO default, the CDO becomes worthless and the CDS contract has to be paid. It is a Ponzi scheme.
6. There was so much predatory lending going on because the lenders didn't own the loans. They were not liable if the loans weren't paid (AIG was left holding the bag, and the taxpayers paid their bill). The original lender collects the 30 year mortgage money by reselling the loans a few days later. This process hasn't changed.
7. TARP bailed out the banks because they owned so much CDOs that they would have become insolvent otherwise. AIG was bailed out because they are the last guys in the pyramid scheme. Otherwise, the whole financial sector would have shut down causing a larger depression than the 1930's.
8. The US financial sector is more deregulated today than in the 1930's, Our government authored this crisis by starting the deregulation in the 1980's and repealing legislation enacted after the Great Depression. This allowed mergers for the big banks we have now and the trading of unregulated derivatives. None of this has changed today.