Is there a specific percentage for a merchant's profit?

There is no specific profit margin in trade within Islam. However, it is not permissible for a merchant to deceive a buyer by selling an item for more than its known market price, exploiting the buyer's ignorance. This is indicated by the hadith: "Do not meet the 'jalab' (merchants bringing goods from outside the city). If anyone meets them and buys from them, then when his master (the original owner of the goods) comes to the market, he has the option (to cancel the sale)." The Permanent Committee for Issuing Fatwas has affirmed that profits are not limited, but it is preferable for a Muslim to be lenient in their buying and selling, and not to deceive (ghaban) others, but rather to observe the right of Islamic brotherhood.