Investors in CBS and Viacom may be growing fretful. They have good reason. On Tuesday, Shari Redstone and her family holding company, National Amusements, sued CBS, countering the angry lawsuit CBS filed against Ms. Redstone and National Amusements two weeks ago.
The back-and-forth legal attacks have plunged both companies into uncertainty and paralyzed any deal-making. Yet investors may still want to stay in the game.
In...