Trump Tweets that triggered algos.
China, Japan, EU Stimulus (more of the same)
Resulting in Euphoria asset price (known as multiple expansion). The problem with the artificial stimulus is the "Law of Diminishing Returns" Eventually it catches up and the Eiffle Tower Formation ensues.
If you understand macroeconomics and have the ability to read a chart bare-knuckle. You will know the probability is we will hed for a World Recession and Stocks will go much further down over time.