The $3 trillion petrochemical market is in danger of freefall if oil prices continue to sink.

Altogether, petrochemical prices are down 14% from May to June, and that's crimping leading PC stocks (most of them located outside the U.S.). But one PC stock may be on the comeback trail, thanks to reports of a major purchase of a U.S. natural gas giant.

First things first. Judging from Platts’ benchmark Global Petrochemical Index for the month of June, the entire global petrochemical market is valued at about $3 trillion, with prices ...