Instead of claiming things to be "perfectly obvious," where is the evidence behind your claim? Before jumping to a conclusion, look at how many sellers were involved on the day the slide started. If you can show that only a small number of investment banks were selling huge quantities of stock all at the same time, you might have a leg to stand on.
Now, even if that were the case, they might have done it for a very good reason, like closing out of leveraged positions that were going south (like the incredibly risky "inverse VIX" trade). And even if that were the case, why was the entire market so spooked to trigger further sell-off? Could it have been the sudden spike in the interest rate and the potential for inflation? Could it have been that the rise of market prices (DJIA) was starting to look parabolic recently, which is a sign that people are getting too speculative and complacent about risk?
It's sad when political partisans jump to conclusions without even one piece of objective data.
RE: Any Steemit conspiracy theorists think the market crash was a false flag to hurt Trump?