To be pedantic, the S&P 500 is a large portion of the stock market, not the economy. Its value is about 75% of the value in stocks. But stocks are only 25% of all stores value. Real estate is twice the size of the stock market. The rest is mostly corporate and govt bonds.

This is why the real estate crash of 2008 caused the Great Recession, while the Internet Bubble bursting was a small recession.