The Prophet ﷺ forbade the selling of foodstuff before receiving it. I consider that all types of sellings should be done similarly.  

سَمِعْتُ ابْنَ عَبَّاسٍ ؓ يَقُولُ أَمَّا الَّذِي نَهَى عَنْهُ النَّبِيُّ ﷺ فَهْوَ الطَّعَامُ أَنْ يُبَاعَ حَتَّى يُقْبَضَ قَالَ ابْنُ عَبَّاسٍ وَلاَ أَحْسِبُ كُلَّ شَىْءٍ إِلاَّ مِثْلَهُ  

The Prophet ﷺ said, "The buyer of foodstuff should not sell it before it has been measured for him." Ismaʿil narrated instead, "He should not sell it before receiving it."  

أَنَّ النَّبِيَّ ﷺ قَالَ مَنِ ابْتَاعَ طَعَامًا فَلاَ يَبِعْهُ حَتَّى يَسْتَوْفِيَهُ زَادَ إِسْمَاعِيلُ مَنِ ابْتَاعَ طَعَامًا فَلاَ يَبِعْهُ حَتَّى يَقْبِضَهُ