Met some of the Singapore Exchange's (SGX's) regulatory staff last week for a media briefing into market manipulation and insider trading. I have to say - what a thankless job they have. On average, they get 120 alerts daily into odd price/volume movements and have to sift through these to see if a query/further investigation is warranted. If they do decide to probe further and if something suspicious is then detected, the case gets sent to MAS or CAD and it may then take years of digging around before anything more is heard. And the "conversion'' rate is low - my guess is only around 10 per cent of these cases actually lead to convictions.
Not surprising then, that there's widespread and ingrained public scepticism with the whole investigative process. Then again, many other countries don't even issue public queries - HK for example, relies on private queries, so the market doesn't know that regulators are involved when they do decide to look at funny movements.
So even if many think SGX's queries are ineffectual, they do at least serve as some kind of signal that something is going on and to keep an eye on things.
The source of the scepticism is most probably the dual role the exchange plays, balancing profit-making with regulation. More on this later...