Two of the largest Chinese bitcoin exchanges, OKCoin and Huobi's Weibo have announced a halt to margin trading in bitcoin, citing guidance from the PBoC. This was guidance, and not an official rule, according to Coindesk's reporting. I have commented on the liklihood of the PBoC cracking down on BTC as a workaround for capital controls, reference The Macro Truth About The Big Bitcoin Pop. As of right now, I have been proven correct.
Expect this action to reduce the volume of bitcoin trading in China. For one, the lack of access to margin may quell volatility on one hand, but also compress liquidity. Without the ability to charge for lending products, Chinese bitcoin exchanges may have to go for plain vanilla trading commissions (which they don't currently have). As a result, expect a move towards parity between Chinese and US/EU bitcoin exchange volumes.
China used to be the king!
Of course, there are other ways to attain leverage in bitcoin transactions, circumventing 3rd parties, hence eliminating central bank influence. It's called Veritaseum (see What is Veritaseum? A Layman's Explanation) and heralds P2P capital markets (see The Onramp to Peer-to-Peer Capital Markets) through Pathogenic Finance (download the report pdf Applied Pathogenic Finance: Wall Street's "Internet Moment" (4.58 MB) ).
Here's the quick video...