In order to analyze the fattening practices and commercial speculations of sheep on the occasion of the Muslim holiday (Aïd El Kebir) commonly known as Tabaski, an investigation is carried out three months before the holding of this festival in the course of the year 2020 in the Tahoua region in Niger. The survey is carried out on a sample of 300 sellers / resellers and buyers from the urban commune of Tahoua and the peripheral village of Badaguichiri. The most important and least important option scaling method was used to analyze the weight of preferences of actors in the sheep fattening value chain. Sheep and the commercial activity of Tabaski sheep remain 100% male prerogative for sellers / resellers and 90% for buyers. The study reveals that sheep fattening is an activity subject to very strong commercial speculation as part of the Tabaski rite. The breed, the color of the coat, the overweight and the conformation of the animals are the preferred criteria in marketing and which are unanimous among sellers and resellers as well as buyers. These criteria come into play in the determination, selection and pricing of sheep for Tabaski. Also, out of a total of six genetic types belonging to four inventoried Sahelian sheep breeds, the Oudah breed is the most presented and appreciated in local markets and outlets. The renewed financial margin linked to commercial speculation around the Tabaski sheep is growing with the increase in the size of the animals. This dynamic of sheep prices can be used by producers and importers as a useful commercial database for scheduling sales at times that open the door to commercial speculation.