It is usually in property buying and selling.
A person C is buying a property just for a quick profit and not intend to hold it as an investment but sell it immediately to another person without completing the transaction from the seller S but to confirm to resell it to another buyer B. He is then acting as a confirmmor ( middle person between the seller S and the real buyer B ) of buying a property. The property so "owned" by this confirmor is then called as 摩貨.
http://www.cantonese.sheik.co.uk/dictionary/words/55138/