The fights over Equinox Minerals and NYSE Euronext cross financial and political faultlines. The first battle is almost over; China’s Minmetals, which made a cash bid for the Australian-Canadian copper miner, has ceded to a higher cash offer from Barrick Gold. The second struggle – rival, mostly share, offers from Deutsche B?rse and a consortium of Nasdaq OMX and ICE – continues.

On the financial side, these disputes are taking place in different domains. The mining fight is in a land of abundant cash flow. Barrick’s cost for mining an ounce of gold was $457 in 2010 – about one-third of the current market price – while Minmetals has the backing of a government trying to find a safe home for foreign currency worth $3,000bn. But in exchange land, throwing cash around is riskier: the typical 20 per cent operating profit margins are less than half the current level in copper mining. No wonder that the mining deal is at 28 times last year’s profits, while the multiples on the exchange proposals are less than 20.

The political divide is different. On one side is economic logic. It makes sense for China to acquire commodities at the cost of production rather than at the exaggerated market price. And it is sensible for exchanges to operate in many countries and markets. On the other side is what is claimed to be national interest. There were probably few tears shed in Ottawa when a local champion displaced a Chinese bid for a partly Canadian company. The politicking around the prestige and jobs that come with independent exchanges seems to be limitless.