Check out the companies making headlines after the bell:

Urban Outfitters shares jumped more than 3 percent in after hours trade but later turned negative, tumbling more than 4 percent on mixed quarterly results. Earnings per share were 83 cents, topping estimates of 79 cents.

The stock turned negative after concerning comments on the conference call. The company's CFO, Frank Conforti, said the company's sales have started out the year weaker than anticipated. He also said the retail segment same-store sales income could come in flatter to low single-digit negative for the first-quarter. It was also noted on the call that fourth-quarter traffic was negative in North America and Europe, with Europe experiencing more significant traffic challenges.

Urban Outfitters reported revenue and same stores sales last month. The retail company earned $1.13 billion in revenue, missing estimates of $1.14 billion. Same stores sales increased 3 percent, while analysts forecast an increase of 4.5 percent.

Shares of NIO tanked more than 8 percent in extended trading after the Chinese electric automaker released its fourth-quarter earnings results, noting a slowdown in vehicle deliveries.

"Deliveries of the ES8 in January and February 2019 were 1,805 and 811 vehicle respectively, which reflect a greater than anticipated slowdown in monthly deliveries compared to December 2018," according to the company release. NIO said the slowdown was mainly caused by an acceleration of deliveries at the end of last year, the seasonal slowdown at the start of the New Year, as well as macro-economic conditions in China, especially in the auto industry.

Shares of Ross Stores ticked more than 3 percent lower in extended trading Tuesday after issuing weak first-quarter guidance, despite strong fourth-quarter earnings. Beating on the top and bottom lines, the company posted earnings per share of $1.20 on revenues of $4.11 billion. Wall Street expected earnings per share of $1.13 on revenues of $4.05 billion, according to Refinitiv.

Ross's same store sales increased 4 percent, which topped estimates of a 2.3 percent increase. The stock moved lower based on weak first-quarter earnings per share guidance: between $1.05 and $1.11, compared to the forecast $1.18.

Shares of AeroVironment rose more than 9 percent after market close Tuesday based on better-than-expected third-quarter earnings. The aircraft company reported earnings per share of 35 cents, beating the forecast 14 cents. Revenue was in line with estimates at $75.3 million.

Ambarella shares jumped more than 8 percent after hours following a fourth-quarter earnings beat. The semiconductor company earned $51.1 million in revenue, topping estimates of $50.9 million. Earnings per share beat at 14 cents, compared to the 4 cents expected by analysts.

Shares of United Natural Foods shot up as much as 5 percent in extended trading following the release of its better-than-expected second-quarter earnings and strong full-year guidance. The grocery store company posted earnings per share of 44 cents on revenues of $6.15 billion. Analysts forecast earnings of 22 cents on revenues of $6 billion.

United Natural Foods issued strong 2019 guidance. It forecast full-year earnings per share between $2.00 and $2.40, compared to the estimated $1.17. The company sees 2019 revenues between $21.5 and $22.0 billion, in line with the expected $21.48 billion. The company's stock later rolled over and dipped slightly negative after hours.