Wall Street was in a pessimistic mood on Tuesday morning, and investors bore the brunt of bad news on the trade front. The U.S. Commerce Department cited human rights abuses in adding more than two dozen Chinese companies to a list of businesses with which U.S. companies are not to work, and Chinese officials vowed to retaliate against their American counterparts. By just after 11 a.m. EDT, the Dow Jones Industrial Average (DJINDICES:^DJI) was down 255 points to 26,223. The S&P 500 (SNPINDEX:^GSPC) fell 31 points to 2,907, and the Nasdaq Composite (NASDAQINDEX:^IXIC) lost 89 points to 7,867.

The morning was a contentious one, as pilots at Southwest Airlines (NYSE:LUV) decided to take their issues up with Boeing (NYSE:BA) in a lawsuit. Meanwhile, Domino's Pizza (NYSE:DPZ) released quarterly financial results that included some troubling numbers, but investors shrugged off business concerns and instead focused on one key move from the pizza giant.

Pilots sue to the MAX

Shares of Southwest were close to unchanged after the company's pilots' union alleged that the Boeing 737 MAX aircraft is unsafe. The suit claimed more than $100 million in lost wages as a result of what pilots called "a calculated decision to rush" the 737 MAX to market, and it alleged that Boeing "abandoned sound design and engineering practices" in "deliberately mislead[ing] its customers, pilots and the public."

Southwest jet on taxiway in desert landscape.

Image source: Southwest Airlines.

The lawsuit noted that the grounding of the 737 MAX has affected more than 30,000 scheduled Southwest flights. Pilots are bearing the financial brunt of that, and concerns are growing about when the 737 MAX will be ready to return to service. Southwest has already planned out schedules assuming that 737 MAX aircraft won't be available until January 2020.

Boeing, whose shares fell 2%, said that it believes the lawsuit is without merit. Yet most still expect the two companies to keep meeting in efforts to reach agreement about the financial impact that the 737 MAX has had on Southwest. Despite its strong reputation for treating employees well, Southwest still faces the potential challenge of keeping its pilots happy even as it seeks to get 737 MAX planes back into flight schedules as soon as possible.

Domino's serves up results

Shares of Domino's Pizza climbed 1%, recovering from losses in the pre-market trading session. The pizza specialist's third-quarter financial results weren't quite as strong as many had hoped, but investors seemed to like Domino's capital allocation decisions.

Global retail sales were up 5.8% during the quarter compared to year-ago levels, but U.S. same-store sales growth came in at just 2.4%. International comps were even weaker, increasing 1.7%. Both figures slowed from last quarter's numbers, and the longer-term trends have been unfavorable for more than a year now.

Fierce competition in the restaurant space has held back Domino's growth, but investors saw a silver lining. Along with the report, the company said that it would authorize a new stock buyback program to repurchase up to $1 billion in stock. With the pizza chain having spent almost $94 million on buybacks during the quarter, shareholders hope the new authorization will make Domino's even more aggressive going forward.

Domino's has done a good job of defending its leadership position in the pizza industry. Even with the prospect of seeing sustained weakness in its core business, Domino's continues to work hard to be the go-to option for pizza-hungry customers across the globe.