In Hong Kong, the Hong Kong Monetary Authority oversees the centralised clearing system in which all the Hong Kong clearing banks (also note issuers) participate. Because Hong Kong's is a 'real-time' settlement system, there is no need for a central counterparty as a 'risk intermediary' because there is no risk.

I explicitly referred to this some ten years ago when the implications sank in of 'Peer to Peer' connectivity - and a decentralised, dis-intermediated 'Market 3.0' -  in the aftermath of a market-centric Dot Com I set up.

Market 3.0: the final version

In a spot transaction the two functions take place contemporaneously and the exchange of value is conditional: if I don't have the shares, I can't offer them for sale, and if I don't have the money, I can't bid for the shares.

The consequence of this is that for true real-time settlement of a spot transaction, there is no requirement for a risk intermediary such as a central counterparty because there is no risk. Where there is an element of time between the conclusion of the contract and its settlement, then this introduces the requirement for risk management, and the interpolation of a risk intermediary such as a central counterparty or insurer.