I've made a lot of money over decades by assuming the economy and the world are very predictable, as long as you don't worry about the inevitable short-term fluctuations. Wall Street tries to get investors to think otherwise so they can skim money from as many people as possible.
The earth turns around, which means the sun rises, people go to work, eat meals, make babies, chose entertainment, solve clothing, solve transportation, solve housing, borrow money, try to improve their living situation, striving for a better tomorrow. This just keeps happening, there are wars, pandemics, scandals and economic disruptions, but the wheels of the economy just keep churning along as people solve life's needs and wants.
Some businesses grow over time, others stagnate, shrink or become disrupted. Things are VERY predictable and that creates profits for those who realize just how predictable these things are.