Carvana posted a wider fourth-quarter loss of $86.4 million as the used-vehicle upstart continued to spend heavily to expand into new markets. Revenue jumped 121 percent to $584.8 million as retail units sold climbed 105 percent to 27,750.

The used-vehicle retailer's gross profit rose 156 percent to $56.1 million during the latest quarter.

The company's fourth-quarter 2017 loss totaled $47.2 million on revenue of $265 million.

The Tempe, Ariz., company has been in expansion mode at the expense of profitability, with one analyst calling Carvana the Tesla of the dealership world . The company said it added seven car vending machines in 2018 for a total of 15 at year end.

Shares in Carvana rose after the report, gaining 7.3 percent to close at $44.86 on Thursday.

Carvana, which offers delivery service in some areas, said it entered 41 new markets in 2018 and now operates in 100 markets.

Full-year results

For all of 2018 , the company's net loss grew to $254.7 million. Revenue increased 128 percent to $1.96 billion. Retail unit sales rose 113 percent to 94,108, and the company's full-year gross profit jumped 189 percent to $196.7 million.

"Carvana closed out a strong 2018 with its 20th consecutive quarter of triple-digit unit and revenue growth. This made us the fastest-growing public auto retailer in the country," Carvana CEO Ernie Garcia said in a statement . "Our ability to execute at even greater scale continues to give us confidence in our path to selling 2 million cars per year . "

For 2019, the company is targeting unit sales of 160,000 to 165,000, or an increase of 70 to 75 percent, and revenue of $3.4 billion to $3.5 billion, an increase of 74 to 79 percent. Gross profit per unit sold in 2019 is expected to total $2,450 to $2,650, up from $2,133 for 2018.

The company said Wednesday it hopes to expand into 50 to 60 new markets this year.