The Barzan wormhole was a passage discovered near Barzan II that was auctioned as a stable route across the galaxy but proved fixed at only one end, stranding two Ferengi in the Delta Quadrant.
The wormhole is introduced in The Next Generation episode The Price. In 2366 the impoverished Barzan offer rights to it to the highest bidder, and the Federation, the Ferengi, the Caldonians and the Chrysalians all send negotiators.
A test flight by Data and La Forge shows that the far terminus wanders. Their shuttle returns just in time, but the Ferengi pod carrying Arridor and Kol does not, and the rights the Chrysalians have won are revealed to be worthless.
Voyager meets the far end in False Profits in 2373. The crew hope to ride it home, but the two Ferengi, fleeing Takar, disrupt it with a graviton pulse. Both ends come loose and the wormhole is lost.