From Quark's rantings, it sounds as if the Ferengi always tried to lurk in the shadows and avoid direct confrontation. With the Feds taking over the galaxy, the Ferengi way of life probably would cease. That wouldn't kill them, though...
The UFP would then shrivel and shrink. But the Ferengi used to live right next door to Earth, even if possibly hiding behind some of Earth's nasty neighbors back in the 23rd century. The Chain wouldn't exactly be running them over then. So they might be around... But possibly still recovering, and keeping low profile till they figure out how to swindle the Orions without losing their lobes.
Timo Saloniemi