On the same day it reported its best quarterly earnings ever, Tsakos Energy Navigation (TEN) suffered a major sell-off in its stock, with the price down more than 17% in late-afternoon trading on Thursday on the New York Stock Exchange.

While the reason was unclear, all fingers seemed to point to a disclosure in the earnings report that TEN had in the past quarter issued 569,207 new common shares to raise $10.4m under an at-the-market (ATM) equity sales programme.

ATMs allow a company to trickle in new shares into the market at times of their choosing without an announcement of a deal, with the results usually not known until a company reports earnings the following quarter.