Stocks had a positive showing on Thursday, with the major benchmarks gaining ground, again led by the Nasdaq Composite. Investors contemplated the growing cost of the devastation left by Hurricane Harvey as Vice President Mike Pence toured the flooded region. Additionally, the Trump administration tapped into U.S. emergency oil reserves in the wake of the storm, which has shuttered nearly 20% of the country's oil-refining capacity. Company-specific news weighed on certain stocks, with Dollar General Corporation (NYSE:DG), International, Ltd. (NASDAQ:TCOM), and Ciena Corporation (NYSE:CIEN) among the worst performers on the day. Below, we'll look more closely at these stocks to tell you why they did so poorly.

Dollar General gets demoted

Shares of Dollar General fell 5.4% following the release the company's fiscal second-quarter report. The dollar store retailer said that sales of $5.83 billion jumped 8.1% over the year-ago period, resulting in diluted earnings per share of $1.08. Investors had been expecting earnings of $1.09 on revenue of $5.8 billion. The company also reported same-store sales increased 2.6% over the prior-year quarter. Due to the better-than-expected results, Dollar General increased the lower end of its full-year forecast for earnings per share to a range of $4.35 to $4.50.

This all seems like mostly good news, so why is the stock falling? Investors may be reacting to the even better financial report last week by competitor Dollar Tree, which used cost-cutting to achieve a 36% increase in profitability, setting a high bar for the retailer.

Downward trend arrow with stock ticker board in background.

Image source: Getty Images.

Ctrip is tripped up

Ctrip stock initially plunged more than 7% in early trading Thursday, then partially recovered to close down 2.4%, in response to the company's second-quarter financial release. The travel services specialist reported revenue of $953.1 million, an increase of 45% over the prior-year quarter, with revenue growth across each of its business segments, and hotel reservations and transportation ticketing seeing the largest increases. Earnings per share of $0.09 compared favorably to a $0.17-per-share loss in the year-ago quarter. Analysts had expected breakeven earnings from $914.4 million in revenue. 

CEO Jane Jie Sun reflected on the quarter, saying, "We are pleased with the strong operating and financial results in the second quarter. Ctrip maintained healthy revenue growth and achieved continual improvement in operating efficiency."

Investors were likely disappointed with the third-quarter forecast provided by the company, which was merely in line with analysts' expectations. also raised concerns that it may be subject to more strict industry regulations going forward, which dampened investors' enthusiasm. 

Ciena's results don't compute

Finally, shares of Ciena fell 11% after the company reported its third-quarter earnings. The computer networking specialist's revenue grew to $728.7 million, an increase of 8.7% over the prior-year quarter, while net income jumped a whopping 79%. CEO Gary Smith indicated the company had gained market share, saying, "Our continued success, combined with strong fundamental demand drivers that are playing in our favor, is drawing a clear division between the winners and losers in the marketplace." 

While the results exceeded analysts' expectations for the quarter, investors wondered why the company offered such a tepid forecast for the remainder of the year, which seemed to be at odds with the strong results it produced this quarter. This may point to the coming quarter being weaker than expected, likely leading to the sell-off.

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.