The market remained kind to investors on Thursday, as the S&P 500 climbed into record territory amid modest advances for most major benchmarks. Positive data on durable goods orders helped keep economists pleased with the state of affairs domestically, and optimism that Republican lawmakers and the Trump administration might be more successful at pushing tax reform forward than they've been with healthcare seemed to provoke a favorable response from market participants. Some companies suffered from bad news that kept them from participating in stocks' overall rise. Gilead Sciences (NASDAQ:GILD), Pier 1 Imports (NYSE:PIR), and PetMed Express (NASDAQ:PETS) were among the worst performers on the day. Below, we'll look more closely at these stocks to tell you why they did so poorly.

Gilead deals with an executive departure

Shares of Gilead Sciences fell 3.5% after the biotech giant said that COO Kevin Young would retire early next year. Young will stay employed through the first quarter and then work in an advisory capacity, according to the company's press release. The decline makes it clear that at least some investors fear some other motive for the departure, but one set of analysts following the stock noted that it's much more important for Gilead to execute well following its nearly $12 billion acquisition bid for Kite Pharma (NASDAQ:KITE). Having waited so long to put some of its cash to work, Gilead needs to show investors that it can compete in the M&A arena against more aggressive rivals in the biotech space.

Gilead Sciences lab technician wearing a white lab coat and purple gloves, in a lab.

Image source: Gilead Sciences.

Pier 1 sinks

Pier 1 Imports stock dropped 7% in the wake of an unfavorable fiscal second-quarter financial report released Wednesday night. The home-furnishings retailer eked out a tiny rise in net revenue on 1.8% growth in comparable sales, but Pier 1 reported an adjusted loss per share that was identical to what the retailer lost in the year-ago quarter, disappointing investors. Moreover, the company also reported on the potential impact from Hurricanes Harvey and Irma on its financials for the remainder of the year, and Pier 1 now expects comps of between negative 1% and positive 1% and weaker earnings than the consensus forecast among those following the stock. The news is particularly unwelcome as it comes after Pier 1 has already had to deal with tough industry conditions earlier in the year.

PetMed Express has more competition

Finally, shares of PetMed Express finished 7% lower. The home delivery service for veterinary prescriptions faces new competition from industry rival PetSmart, which started offering online ordering, automatic refills, and home delivery of its own for prescriptions and other pet products. PetSmart, which went private back in 2015, clearly wants to grab a piece of the lucrative e-commerce business, and investors fear that the alternative option could hit PetMed's share of the market. Coming off a scandal last month involving alleged improper marketing of opioid-based medications for pets, PetMed will need to show it can fight back against PetSmart and retain its leadership position in the pet retail industry.

Dan Caplinger has no position in any of the stocks mentioned. The Motley Fool owns shares of and recommends Gilead Sciences. The Motley Fool has the following options: short October 2017 $86 calls on Gilead Sciences. The Motley Fool has a disclosure policy.