The Singapore Exchange’s $8.3bn bid for the Australian Stock Exchange is probably the only deal that could be done today to consolidate Asia’s bourses in the face of surging competition from alternative platforms. But with the ink hardly dry on the offer document, it is already beginning to look like a deal that may not make it.

The bid marks an important moment in Asia’s snail-like process of coming to terms with the fragmentation of securities trading as dark pools and other alternative platforms arrive from the US and Europe.

So far, the new platforms have been handicapped by the region’s multitude of country-based regulatory regimes, which make it difficult for new entrants to build scale. But Magnus B?cker, the energetic chief executive of the SGX, is right in judging that national rules will not hold the competition at bay for ever. The only answer is for the traditional exchanges to get bigger and cheaper before they are overwhelmed.