What happened

Monday is looking like it's going to be a rough one for Boeing (BA -0.33%) investors, with shares of the aerospace giant down 8.8% as of 1:50 p.m. EDT.

Granted, down days are no novelty to Boeing shareholders, who've seen more than half their investment's value vaporized since the market fell apart in late February. Still, today's decline seems particularly unfair.

Glowing red stock chart arrow trending down

Image source: Getty Images.

So what

Why? But because there's actually no new news out today that would explain the stock's sudden fall. Not an earnings warning, or an analyst downgrade, or even a reduction in price target has been announced -- nothing at all.

Rather, what's dragging Boeing down today appears to be a simple equal and opposite reaction to the stock's recent resurgence in price.

Over the past 10 days, you see, Boeing shares have enjoyed a remarkable comeback, soaring 66% on hopes that the company would win a big cash bonanza from the government's planned CARES Act. The government did in fact finally come through with the relief package, but in a pretty clear example of "buy the rumor, sell the news," investors today are taking their profits, and selling off Boeing stock.

Now what

So where does this leave us? Looking for the next catalyst to lift Boeing shares back up, I fear.

The problem is, most of the news regarding the air travel industry for the foreseeable future is probably going to be bleak. On Friday, American Airlines announced that rather than planning for air travelers to gradually return to the skies in the coming months, it's decided to cut more flights in May than it is cutting in April.

In other words, things look likely to get worse before they get better -- for airlines, and for Boeing as well.