Volatile PetroChina shares top speculative purchases

PetroChina Co has about 11 billion barrels of oil reserves, half a million employees and sales that exceed the annual economic output of South Africa.

Not too long ago, stats like that were important to traders of PetroChina shares. Now, they could hardly matter less.

As State-linked funds intervene to prop up the nation's sinking stocks, PetroChina has transformed into a speculative bet on how much money the government is plowing into equities on any given day. The $310 billion oil producer's top weighting in the benchmark Shanghai Composite Index makes it an ideal target for funds trying to influence the broader market.