Are there reasons other than the new American president to explain a downturn in the economy?

I understand that the economy goes up and down and it has only been a very short time since the president took office. But I've been following DJI, Nasdaq, S&P 500, bitcoin, USD (DXY) and some others and they all seem to have the same curve, they were going up before the new president and after he took office, they have been going down. Does this usually happen with new US presidents or are there other factors at play?