Shares of used-car selling platform Carvana  (CVNA - Get Report) were rallying more than 17% in premarket trading after the company predicted it would sell more cars in 2019 than a year earlier.

The company, which reported wider losses in the second quarter, said it sold 44,000 cars over the three months, an increase of 95% from the same period in 2018.

The adjusted loss in the quarter was 40 cents a share vs. a loss of 37 cents in the same period of 2018. Investors had expected Carvana to post a loss of 39 cents a share.

The company said it expects to sell between 167,500 and 172,000 cars for all of 2019, which would be an increase of between 78% and 83% from 2018. Such sales would result in revenue of $3.6 billion to $3.6 billion over the period, an increase of 84% to 89%.

Gross profits per unit sale hit $3,132 in the second quarter, up from $2,173 in the same period a year ago.

That trend of increased gross profits isn't new.

Looking back further, gross profit margins for the company have almost tripled to around 14% in the second quarter, up from 5.3% for the whole of 2016. Carvana said it thinks it can get to between 15% and 19% longer-term.

Carvana shares rose 17.08% to $67.80.

Constable owns none of the securities listed in this story.