The White House said Monday it is worried about the U.S. stock market sell-off. "We're always concerned when the market loses any value, but we're also confident in the economy's fundamentals," an official said in a statement to CNBC. The Dow Jones industrial average briefly fell more than 300 points Monday morning and the S&P 500 traded about 0.75 percent lower, extending last week's plunge. President Donald Trump has touted the strong stock market performance since his election win and has yet to deal with a significant market pullback. The Dow is up more than 30 percent since the election.
