Their voting power at the IMF is only 10.3 percent.
They have decided to stop waiting for the US Congress to ratify reforms to that voting structure. At their sixth summit recently they announced the formation of their own investment bank, with $100bn in funds, and which they take it in turns to chair.
This institution is still much smaller than either the IMF or the World Bank. But this is as much as anything a political statement about the rising power of these five countries.
And when China, especially, is about to surpass the USA as the world’s leading economy, it makes little sense to call any of these nations “emerging” any more.