The stock market's rebound on Thursday was short-lived. The Dow plunged more than 500 points at one point Friday morning thanks to a slew of concerns, including disappointing earnings reports from Amazon and Alphabet, the parent of Google. Worries about tariffs and economic slowdowns in China and Europe added to the selloff atmosphere, reports the Wall Street Journal. “All the macro issues, from higher interest rates to slowing growth in China are giving us a half glass empty situation regarding 2019 earnings,” Alec Young of FTSE Russell tells MarketWatch. Around 11am, the Dow was down 465 points, or 1.8%, while the S&P 500 was down 2.4% and the Nasdaq 3.1%. (More stock market stories.)