Check out the companies making headlines before the bell:

Snap – Shares of the Snapchat parent plunged 19.5% in the premarket after the company warned of slowing growth due to the recent changes in Apple's iOS privacy rules. Those rules make it more difficult to gather information from users and target ads. Snap did beat estimates by 9 cents with an adjusted quarterly profit of 17 cents per share, but its revenue was slightly short of Wall Street forecasts.