What's your opinion of why oil prices have plummeted?

Greg is a moron. The drop in oil prices has very little to do with the US.

It has far more to do with an over supply in oil, relative to demand (More efficient power plants, cars, etc. are using less fuel to do everything that they do), and a slow down in the Chinese economy, meaning that they are buying even less than just increasing efficiency would have them buy.

Thus, when supply stays the same, and demand drops, prices drop, as well. Plus, there is a speculative part to the oil market, as with any major commodity, and the expectation that Iran's oil, until now boycotted, will soon come into the market, makes the prospect of even more over supply that much more likely.

It is the Iran deal and the Iran oil flowing into the market. Market manipulation is over now with uncontrolled amounts of oil going onto the world oil market. This is why Republicans always want war because it drives up the price of oil. That is the reason they opposed the Iran deal.

Easy.it's pressure to try to collapse Russia and Venezuela, remember when we were told high gas prices resulted from the "unrest" in the Middle East? Still the same. Remember when we were told OPEC was goading us? OPEC doesn't even provide 9% of our Oil. Supply and Demand? Refineries? All BS...The Big Banks have already admitted they manipulate prices and speculation: https://www.google.com/?gws_rd=ssl#q=big+banks+adm...

OPEC stepped up production to deliberately flood the market (and cause the price to collapse) to put North American Tar sands processors out of business.....

In a few months (when it will be too late to resurrect those operations, so they would need to make massive up-front investments (again!) to start over, OPEC will ramp down production, and oil will go back to ~US$100 a barrel....

• A slight loss of demand as alternative fuels come into use.

• A slowing economy in the third world, Russia, and parts of Europe.

• Over-production in the United States, much of it coming from shale oil fields.

• Over-production in Saudi Arabia intended to bankrupt the shale oil producers.

• Over-production in Russia, as they try to make up for lower prices with more sales.

• None of the current producers is willing to stop, fearing financial loss, so they're all hanging on hoping the other guy quits first and prices go back up.

Technically, refinement just went through an experimental growth period that may have found stable conventions of method of assuring longest carbon chains as possible. Price demand may have eased also from completion of some Mexican facilities that greatly eases Old World dependencies and their ever-haggard political ramifications.

All of the above and more. Technological advances in fracking and horizontal drilling have also increased the supply of oil. The latest drop has been Iran. With the dropping of sanctions on them, now THEIR oil will be hitting the worldwide market too.

Warmer winters in the US for the past five years or so have reduced demand, though I'm sure there's more to it.

Many reasons, but bottom line it's the speculators who create fluctuations.

War in the Middle East.