Please dont look at a gdp chart without looking at what happened during a presidency..... Obama presidency pretty much started with the housing market crash, he did a damn good job in repairing the economy and it took 5-6ish years to repair it, which only in the tail end of his presidency it started to become strong.
So of course right when Trump gained presidency the economy is strong, Trump is just enjoying the fruit of Obama's hard work, so Trump didn't do **** yet, other than spend time just Tweet nonsense all day so far. And you know the market is going to go down next year till the end of his term if does not back pedal. More than likely it will take the entire next presidents term to repair Trumps dmg he done to the economy.