NEW YORK ( TheStreet) -- As soon as the verdict on BP's ( BP) liability for the 2010 Deepwater Horizon spill was announced on Thursday, the stock plunged. The move was expected. It may have been overdone. BP will survive.
As the trading day wore on Thursday, the stocks of other U.S. oil producers fell, as well. EOG (EOG) , a leading producer in the Eagle Ford shale formation in Texas, fell 2.9%. Pioneer Natural Resources (PXD) , a leading player in the Permian basin, which is also in Texas, fell 2.9%. Whiting Petroleum (WLL) , a leading producer in the Bakken shale rock formation in North Dakota, fell 4.3%.
Read More:10 Stocks Carl Icahn Loves in 2014
It wasn't all about oil prices falling. Crude dropped just 1%, with West Texas Intermediate, the U.S. benchmark, ending the day at $94.45/barrel.
Instead, the fall in oil production stocks seemed to be more about costs and the dawning realization that finding oil is no longer the same thing as making money from it.
Fracking costs as much as $70 per barrel by some estimates. Fracked wells cost more to put in and they produce less product before depleting.
Oil infrastructure also costs money, but without it, margins fall further.
In the Bakken formation for instance, it can cost $10 to $15 per barrel to transport crude by rail to refineries on the East Coast, compared with $5 per barrel for transportation via a pipeline. Transport by real is a risky business, as a train derailment in Quebec last year showed.