1. Stock prices follow trends. Increasing stock prices make stocks more attractive. These are the foundations of financial bubbles. History repeats itself.
2. Most of the valuation of an index like the S&P 500 is derived from a few stocks. 17.5% of the S&P 500 is the valuation of FAAAM.[0] Take a look at other members of the top 30 like Proctor & Gamble, Johnson and Johnson, Visa, Mastercard. The S&P 500 is mainly composed of companies essential to the daily functioning of the average American's life.
3. The stock market is essentially an unknowable process. Even the most profitable trading firms making billions of dollars a year make countless unprofitable trades each day and will go for years without turning a profit.
[0] https://www.cnbc.com/2020/01/28/sp-500-dominated-by-apple-mi...
Yes, and I don't understand it. The S&P500 is within 8% of its all-time high (3393). Even without a second wave of coronavirus cases and deaths, the current levels of unemployment, defaults, and bankruptices, I can't see what supports these asset price levels. Any ideas?
Add that demand with demand from rich people from other countries for the same services (who might just loot their country and therefore aren't subject to the same domestic economic pressures) and prices keep going up.
The market is effective at allocating funds among equities, but the overall valuation of the equities market is another issue entirely.
https://www.forbes.com/sites/greatspeculations/2018/11/19/pe...