
The S&P 500 monthly chart for 11/12/2019
UBS has published information that more than half of the largest investors expect global markets to fall in 2020. At the same time, investors keep at least 25% of their funds in money as insurance against falling stocks.
As shown above on the S&P 500 chart, you can see that the market is really quite ripe for a large-scale correction.
Possible causes of the fall include new aggravations of the Trump trade war between China and the US, as well as the presidential election in November 2020.