Here’s why GE Aerospace stock crashed today.

GE Aerospace‘S (GE -4.00%) As of 11 a.m. ET today, the stock was down more than 5%. It’s not often that you can blame a stock price drop on an analyst downgrade from another company, but in this case, it is. Wells FargoDowngrades to GE’s key partners; BoeingIt sent shockwaves through the stock prices of both companies.

Should GE Aerospace’s outlook also be revised downward?

Wells Fargo analysts have downgraded Boeing stock to undervalued, arguing that Boeing’s cash flow struggles will hit the aircraft manufacturer’s next investment cycle. That’s a problem for GE because it is the leading engine supplier to Boeing. CFM International, a joint venture, provides the sole engine for the Boeing 737 MAX, while GE provides the sole engine for the Boeing 777X and one of two engine options for the 787.

Image credit: Boeing.

Any pushback on the development of new Boeing models would be negative for GE, especially since the company develops engines in anticipation of Boeing’s developments. GE typically makes money by servicing aircraft engines for years after they are sold on new planes.

What This Means for GE Aerospace Investors

This is just an analyst’s opinion, but it is based on solid evidence: Boeing is unlikely to meet its medium-term cash flow targets, and developing a new aircraft will take years and cost a lot of money.

Still, it’s worth noting that Boeing isn’t going to give up airplane manufacturing any time soon. And while the potential capital raising (to fund new aircraft development) isn’t good news for Boeing shareholders, GE investors should be agnostic.

Ultimately, the airplanes produced with the financial support of the equity financing are likely to be similar to those produced without the equity financing, and GE Aerospace will benefit equally.