Arabic (بيع النجش) for a type of impermissible sale (ba’i muharram) whereby a person (fake bidder/ ghost bidder/ phantom bidder) offers a higher price (thaman) for an item without a real intention to buy it, but just to cheat or defraud another person (bidder) to drive up the price (beyond ordinary and reasonable levels). The person practicing it may collide (through tawatu’) with the seller to bid prices up in the presence of potential buyers (real bidders) only as trickery means to entice them to pay more (just to the benefit of the seller and the colliding party).

This type of sale is also known as ba’i al-munajashah.