Key TakeawaysSnap shares plunged in extended trading after the Snapchat parent issued a third-quarter revenue forecast that disappointed investors. Guidance for adjusted EBITDA was also lower than analysts expected. Snapchat said it would offer further updates at a "Partner Summit" on Sept. 17. Shares of Snap (SNAP) were hit hard in extended trading Thursday, dropping after the Snapchat parent offered a third-quarter revenue forecast that disappointed investors. The social-media company's shares can move dr ...