The threat of bigger media mergers may have hit the pause button. But don’t get too comfortable.

Early last week, the Federal Communications Commission had “serious concerns” about the $3.9 billion Sinclair Broadcast Group/Tribune Media merger. In particular, it focused on Sinclair’s fuzzy efforts to sell off some stations in markets to come under the current 39% U.S. TV household cap, which represents all the TV stations one company can own.

The FCC order asks an administrative law judge to rule on the matter. And, for many, that is a death knell to the deal.

Some evidence of this comes as TV station group stocks fell last week. Investors aren’t happy.

Over that five-day period, Tribune stock was down 14%; Sinclair was off 18%. Other station groups also took hits: Nexstar Media Group losing 7%; Tegna, off 10%; Tronc, a 6% pullback; and Gray Television, sinking 2%.

Concerning Sinclair/Tribune, Barton Crockett, media analyst for B. Riley FBR, said: “We would assume that if the FCC had these feelings, it would have expressed them privately to Sinclair before issuing this statement, and that Sinclair would have heard enough to adjust its divestitures before we got to this point.”