George Economou now holds more than 70% of the stock in DryShips, in what may be his largest concentration since its New York initial public offering in 2005.
In percentage terms, the Greek shipowner's control of the stock is nearly 10 times the 7.5% holding he reported in the company in September 2016.
The latest bump is not the result of Economou having acquired new shares, but rather a function of a $50m stock buyback programme the company announced in February.
