Most trading in bitcoin takes place in China: Huobi and OKCoin, two Chinese exchanges, are thought to account for more than 90% of transactions. The currency seems to have become an outlet for Chinese savers frustrated with their limited investment options and searching for high-yielding assets. The Chinese authorities are worried enough to have banned banks from dealing in bitcoin, but individuals are still free to speculate and have been doing so with gusto.
That is from The Economist. It is consistent with my view that Bitcoin is a largely mature technology, used mostly for evading Chinese capital controls.