Sayyiduna Abdullah bin Abi Awfa (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) said: "The one who places a fake bid (to raise the price) is a consumer of usury (riba) and is accursed."
Al-Tabarani recorded it in al-Mu'jam al-Kabir, and its narrators are thiqat (trustworthy), except that I do not know of al-Awwam bin Hawshab having heard from Sayyiduna Ibn Abi Awfa (may Allah be pleased with him). And Allah knows best.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب البيوع / 6375
Sayyiduna Ismah (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) said: "There is no protected pasture (hima) in Islam, and there is no (permission for) placing fake bids."
Al-Tabarani recorded it in al-Mu'jam al-Kabir, and its chain is da'if (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب البيوع / 6376
Hadith Gradingمحدثین:إسنادہ ضعیف
Hadith Takhrij«اخرجه الطبراني فى المعجم الكبير (178/1)»