PS. Even IF the most recent bitcoin price rally (started 2015-11-24) is indeed due to the Chinese crackdown on UnionPay abuse, it may not cause intervention on the Chinese bitcoin exchanegs.

When the Chinese citizens used the UnionPay route, they took yuan out of the Mainland economy, and some of those yuan ended yp in foreign hands.  From the perspective of the Chinese central bank (PBoC), that is bad.  For one ting, those yuan could be ammunition for speculative attacks against the currency; in order to fight such attacks, the PBoC would have to spend some of its reserves of foreign currency.  Anyway, the net result would be the Chinese population becoming poorer relative to the rest of the world.

With the bitcoin way, hoewever, the yuan will remain all in the Mainland.  The Chinese citizens will take the "worthless" bitcoins, cheaply made in China, and sell them to foreign buyers for foreign currency.  Some of that foreign currency will find its way in the PBoC coffers, some will be used by the Chinese to buy property abroad.  Either way, the net result will be the Chinese people becoming richer relative to the rest of the world.

If this analysis is correct, the good news (for traders) is that the PBoC is unlikely to intervene and restrict thet trading of bitcoins at the exchanges.  On the other hand, the price may drop once the Chinese who are buying bitcoin in China for that purpose will start selling them in the "Western"  exchanges. (Maybe this is the cause of the recent drop to ~$430).

By the way, this chart may be evidence that the rallies of the last three months are due to real demand, rather than manipulation in the exchanges.  Note that the total transaction value (in USD/day, excluding return change outputs) in the blockchain, which dropped at the end of 2013 and has been nearly flat for 20 months, climbed suddenly since 2015-11, together with the trading volume inside the Chinese exchanges.  This is consistent with the MMM and bitcoin-exporting theories: hoarders send their BTC to the Chinese exchanges, a different set of people withdraws them, and deposits them to foreign exchanges.