Sweetgreen $(SG)$: Shares of the fast-casual salad chain slumped 15%. The company said its second-quarter loss widened and it lowered its outlook as the cyclosporiasis outbreak weighs on demand.

Airbnb $(ABNB)$: The short-term rental company raised its forecast for the year citing a ramp up in global demand as it uses artificial intelligence to improve its platform. The stock rallied 11%

DraftKings $(DKNG)$: DraftKings' second-quarter revenue fell, as sports bettors won their wagers and the company offered promotions to attract new customers. Shares fell 3%.

Instacart $(CART)$: The delivery platform, formally known as Maplebear, issued an upbeat outlook for the current quarter. Shares jumped 9% afterhours.

Monster Beverage $(MNST)$: Shares in the energy-drink company edged higher less than 1%. It reported higher second-quarter revenue and profit, boosted by growth in sales to customers outside the U.S.

Rocket Cos. $(RKT)$: The mortgage finance company reported adjusted earnings were 16 cents a share, in line with analysts' expectations. Shares ticked lower 3% in postmarket trading.

DoubleVerify $(DV)$: The digital-media software company is being acquired by Nielsen Holdings, the companies announced. Shares in DoubleVerify advanced more than 10% after-hours.