There's one major thing that could make Boeing shares bounce, according to wealth manager Mark Tepper.
The aircraft manufacturer has been under pressure since global airlines grounded all 737 Max planes following a second deadly crash of that model in under five months. On Monday, Boeing CEO Dennis Muilenburg told CNBC the company was aiming to have the popular jets back in the air by the end of 2019.
"Once they get the Max back in the air, they suddenly become a cash cow again," Tepper, president and CEO of Strategic Wealth Partners, said Wednesday on CNBC's "Trading Nation."
"I think it's important to understand that their cash flow burn right now is just a timing event," he said. "They are still going to realize that cash flow, it's just pushed out a few quarters."
Tepper added that Boeing is also involved in negotiations with Chinese airlines on what would be the largest-ever order of its larger two-aisle jets, according to a Bloomberg report.
"The earnings and cash-flow growth are still there for Boeing. The stock just happens to be in the penalty box right now until the Max is back in the air," Tepper said. "And once the Max is flying again, Boeing's stock is going to start flying as well."
JC O'Hara, chief market technician at MKM Partners, disagreed, saying he prefers smaller aerospace and defense names to the likes of Boeing and Raytheon. Those larger companies' stocks tend to mask the "underlying strength" of the broader aerospace and defense sector ETF when they fall under pressure, he said.
"One of the names we really like is L3 Technologies. Stealthily, it's risen 45% year to date, and again, if you just look ... at the index, you're not going to see that " because of Boeing's months of underperformance, O'Hara said in the same "Trading Nation" interview.
"I think this is an area where we want to look at the smaller names because they have been the outperformers and we think that strength continues," the technical analyst said.
The iShares U.S. Aerospace & Defense ETF, which tracks the broader sector, is up almost 22% year to date. Boeing shares, which have lost nearly 21% since their peak on March 1, are still up about 8% this year.
Disclosure: Tepper's firm owns shares of Boeing.