Uruguay’s first tech unicorn, Dlocal, named e-commerce veteran Pedro Arnt as its co-chief executive officer as the firm seeks to restore investor confidence after a short seller attack and a probe in Argentina crushed its stock.

Arnt, who left the post of chief financial officer of e-commerce giant MercadoLibre Inc. last week after almost a quarter century at the region’s most valuable publicly-traded firm, will serve along chief executive office Sebastian Kanovich.

Dlocal’s US-listed shares rose as much as 26% in late trading, adding to gains after Bloomberg News reported yesterday that the company was exploring a sale. The shares were little changed for the year at today’s close.