the reason is: because the "payment for both the money and the goods" can't really be realized in the transaction of second-hand houses, that is, the buyers and sellers can't deliver the "property right certificate and the house payment" immediately after the house transaction is concluded, but the buyers often get the property right certificate after paying the house payment (down payment or full payment) for 1-3 months. During this period, the transaction funds of second-hand houses are basically deposited in the account of the brokerage company, and the account funds are not supervised, so that they can be traded.

In addition, the intermediary company can't collect and pay the transaction funds on behalf of customers, thus avoiding the possibility of the intermediary company misappropriating the customers' funds, and further preventing the recurrence of the "runaway with money" incident of bad intermediaries.