What happened

When it comes to Boeing (BA -0.62%), Credit Suisse sees the glass as half empty, and has initiated coverage of the aerospace giant with the bank's equivalent of a sell rating. Investors are taking note, sending shares of Boeing down as much as 3% in Wednesday trading.

So what

Boeing has endured a difficult stretch, dealing first with issues with its 737 MAX and more recently with the effects of the pandemic. The company's total debt has ballooned by 400% in the last five years because of a drop in cash flow due to fewer deliveries to airlines.

Boeing is on the comeback trail, but has a long way to go. Credit Suisse analyst Scott Deuschle is advising investors not to jump in headfirst, initiating coverage on the stock with an underperform rating and assigning it a $98 price target. That target is one of the lowest among Wall Street analysts. 

Deuschle views aerospace as a "zero sum" game, and believes Boeing is on the wrong side of the equation. He expects continued tensions between the U.S. and China to weigh on its sales, and predicts the company will face challenges as it attempts to boost orders and cash flow.

The 737 MAX was grounded for 18 months in the U.S. and much of the Western world while Boeing worked through engineering issues that caused two fatal accidents. But it has not yet been cleared to resume service in China. There have been some recent signs of progress, including the first international operator of the MAX authorized to fly the plane over China, but many analysts believe the delays are tied to broader geopolitical tensions.

Even after the MAX is cleared by Chinese regulators, there is a risk the Chinese government will push its airlines to favor planes made by Boeing archrival Airbus (OTC: EADSY).

Now what

Boeing reported improving delivery stats for the third quarter, and the company does appear to be on the rebound. The question for investors is how long that recovery will take. Between Deuschle's China concerns and broader fears that a slowing global economy could cause airlines to defer orders, there is a lot of uncertainty surrounding Boeing right now.

Among commercial aerospace-focused companies, Credit Suisse rates TransDigm Group and Heico as outperforms and is neutral on Raytheon Technologies. On the defense side, the bank favors Northrop Grumman, L3Harris Technologies, and BWX Technologies. If the next few quarters play out the way Deuschle expects them to, there are better opportunities out there right now than Boeing for aerospace investors.