Since the government changes in Doha a couple of weeks ago, one issue has been at the front of minds in the London banking community: will Qatar's aggressive global investment philosophy be curtailed under the new regime?
Qatari investors have stakes in British companies ranging from the supermarket group Sainsbury's to the London Stock Exchange, and from Barclays Bank to BAA, the organisation that owns London's Heathrow and other airports in the United Kingdom.
Added together, those holdings represent about US$10 billion of current equity value.
Non-listed investments, like Harrods, The Shard and other property interests, are also significant. The value of the Qatar government's UK portfolio is probably nudging the $20bn figure.
Private investment by wealthy Qataris, in anything from super-prime residential property to horse racing bloodstock, would increase that total significantly.
One banker who has done business with Qatar said: "I think it [the government changes] will have an effect on future investment policy. It will become less shoot from the hip and more cautious, partly because of changes of personnel at the top, where decisions are made. But also because the global investment climate is different now."
He pointed to the speech by the new Qatari emir, Sheikh Tamim bin Hamad bin Khalifa Al Thani, in which he said he wanted not to appear "arrogant" in the business world, as a sign of this new caution.
A London source close to Qatar Holding, the principle foreign investment vehicle, said future policy was still being shaped.
"The 'arrogant' theme of the speech has not been picked up by Ahmad Al Sayed [the new chief executive of the Qatar Investment Authority, the owner of Qatar Holding]. He will be the guy who shapes policy and executes things.
"But it might well be that there will be a change of emphasis. After all, the world has changed since the early days of Qatar's foreign investments.
"The financial crisis enabled them to make big, bold returns - 17 per cent per year over five years looks a reasonable figure. Are those kind of returns still available? Probably not unless there's a big banking crisis in Asia or something like that."
But the source, speaking on condition of anonymity, insisted: "Ahmad's job is to make money for Qataris, and he will be looking round the world for opportunities."
He declined to speculate on whether Qatar might be inclined to consider disposals of some of its UK assets.
Some, like the stakes in the London Stock Exchange and Sainsbury's, were bought at high prices before the financial crisis, but the recovery in equity prices might make disposals more likely.