Will Fox shift some of its biggest network affiliates from Sinclair Broadcasting to Ion Media as part of a battle for fans of politically conservative commentary — or just reduce its dependence on Sinclair as it grows? Wall Street believes that’s a real possibility.

Sinclair shares are down 7.6% this morning following a Bloomberg report about Fox’s talks with Ion.

The news service says that Fox and Ion are weighing a joint venture to include stations each company owns. If it comes to fruition, Fox would switch its network affiliation from five Sinclair stations to Ion ones this year.

In addition, Fox would flip affiliation at 14 Tribune Media stations once Sinclair completes its $3.9 billion deal to buy the broadcast company.

Fox apparently is concerned about Sinclair’s efforts to promote conservative commentary at its local stations — making it a potential challenger to Fox News — as well as the broadcaster’s growing clout.

If Fox follows through on the plan then “it would be a meaningful negative” for Sinclair, RBC Capital Markets’ Leo Kulp says in a report.  The local broadcaster has affiliation deals with Fox in 35 markets and 14 with Tribune.

Ion stations could replace Sinclair in seven markets, and Tribune in 11.

But Kulp warns that “this may be a negotiating ploy.” Ion doesn’t have local news, sales, or an engineering infrastructure. The loss of local news “and lead-in programming could have a meaningfully negative impact on Fox primetime ratings.”

Last month HBO’s John Oliver blasted Sinclair’s policies regarding “must-run” pieces for its stations including commentary from President Trump’s former senior advisor Boris Epshteyn and frequent reports from a “Terrorism Alert Desk.”

“Sinclair and its digital news subsidiary Circa not only produce and send packages to their stations; they even write scripts that local anchors use to introduce the pieces,” Oliver said.

Sinclair CEO Chris Ripley recently told our sister publication, Variety, that critics “mischaracterize what we do by just focusing on a small subset of our newscasts.” The commentators Sinclair promotes are on “because we are optimizing for ratings. They represent a diversity of views that you can’t find on other channels.”