NEW YORK ( TheStreet) -- Dry-bulk earnings season has begun, and if the early returns offer any indication, it's going to be a kind of boring third quarter. And that's a good thing, because what have decidedly not been boring are the volatile ups and downs in the broader equities markets, driven by economic data reports that signal recovery one day and entrenched recession the next. Like everything else this week, especially commodities-related names, the shares of shipping companies have been violently whipsawed by investors. DryShips ( DRYS), for instance, ended Friday by losing nearly 5% to close at $6.04. The loss erased a 5% jump in value on Thursday, which followed two straight sessions of sharp declines, when the stock surrendered nearly 13%. Because dry-bulk shares are high beta, big moves in broader indices are magnified in the maritime names. Indeed, every dry-bulk stock moved in similar fashion this week, rocked by the heavy seas. But back to earnings: This week, DryShips and Genco Shipping & Trading ( GNK) released quarterly results that surpassed Wall Street targets -- the former by 7 cents a share and the latter by 9 cents. Both appeared to benefit from interest expenses that came in at a lower rate than many had foreseen. Otherwise, the results of both operators showed that year-over-year comparisons remain bleak, but that China's raw-materials buying binge, which spurred record imports of iron ore and other commodities all summer, stabilized the shipping industry's profits.