Shares of Carvana surged over 30% in extended trading on Thursday after the used-car seller forecast a surprise rise in current-quarter retail sales and core profit.

Carvana’s results come as high interest rates prompt consumers to look for deals on second-hand cars instead of buying new ones.

Its shares, which have a short interest of 27% of free float, are up about 65% this year after recording an 11-fold rise last year.

The surge in its stock price is set to add about $5 billion to its market capitalization of $17.6 billion, as of Wednesday’s close.

The used-car retailer said it was expecting a sequential increase in adjusted core profit and growth rate in retail units in the second quarter, while analysts expected a 2.6% fall in retail sales from a year earlier.

Revenue for the first three months of the year was $3.06 billion, beating analysts’ estimates of $2.89 billion, according to LSEG data.

“Revenues beat expectations by quite a bit and expenses remained flat … big upside surprise,” Huber Research Partners analyst Douglas Arthur said.

Adjusted earnings before interest, tax, depreciation and amortization in the first quarter were $235 million, exceeding capital expenditures and interest expense. Analysts had expected $135.9 million in adjusted core earnings.

The company reported a first-quarter profit of $49 million, compared with analysts’ estimates of $31.2 million, according to LSEG data.

The total supply of unsold used vehicles on dealer lots across the United States rose 9%, to 2.27 million units in March from a year earlier, according to market research firm Cox Automotive.

Last month, Carvana’s rival CarMax missed analysts’ estimates for fourth-quarter results and said it might not meet its long-term vehicle sales target.