What happened

Shares of dry bulk shipper Star Bulk Carriers (NASDAQ:SBLK) sank 17.9% in the month of May.

So what

Star Bulk Carriers reported its fiscal first-quarter 2017 earnings last month. The news wasn't great, but you can't really put all of the blame for Star Bulk's downfall on its earnings report.

True, Star Bulk's numbers weren't great. The company lost $0.26 per share on the quarter. But that loss was significantly less bad than the $1.11 per share it suffered in the first quarter of 2016. Plus, revenue surged 40% to $64.9 million. On balance, I find it hard to call first-quarter 2017 a "bad" quarter for Star Bulk, given how much worse the year-ago quarter was. Plus, the earnings report came in the last week of the month. 

Dry bulk ship and tug boat

Star Bulk Carriers stock could use some help, but the BDI isn't helping. Image source: Getty Images.

Now what

No, if you ask me, the real reason that Star Bulk stock fell so hard last month owes to the generally gloomy climate pervading the dry bulk sector as a whole. Consider that the Baltic Dry Index (BDI), which tracks dry bulk shipping rates globally, entered the month of May at a level of 1,109 points (1,000 points is the index's baseline). Over the course of the month, it fell 21% to end at 878. Those numbers actually tally pretty closely with Star Bulk's own 18% drop in stock price in May -- Star Bulk incurred most of the losses before reporting its earnings.

It almost seems to me that investors don't care how Star Bulk's business is doing -- or the improvements it's showing. As long as the BDI is pointing down, so too will Star Bulk Carrier's stock. That is why I have to break this bad news to you now: The BDI is down a further 7% so far in June.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.