In the financial world, different markets are correlated more tightly than most people anticipate. It is also evident how one single individual can effectively influence markets to move in certain directions, either knowingly or by accident. When President Trump Tweets weird stuff, the markets do indeed respond in mysterious ways.
Back in September of 2012, Donald Trump claimed how the Obama and Bernanke team was effectively destroying the value of the US Dollar. It is certainly true this currency has had a few rough years in the wake of the 2008 financial crisis. Then again, this goes for most currencies and even non-currency financial markets, which all saw a bloodbath in one way or another.