Oil Price Speculation

Huge changes in demand and supply over the last several years (shale gas, Iran-Iraq and global slowdown) account for the bulk of changes.

There is some anecdotal (and perhaps other) evidence of a cobweb cycle; supply responds to prices with a lag

In the price movements there is a fundamental and a speculative component.

The term "speculator" is itself a bit fuzzy. I note one paper that attempts to define the term and the issue, though there are others.
-see background information here

Speculators just don't have enough capital to hold oil prices artificially high, or low, for months at a time.

Don't know how to answer this. Are airlines buying forward contracts to lock in prices speculators or acting on planned demand for fuel?

funny how you never hear about speculators on the way down

i am unaware of any systematic evidence relating speculation to "large movements in monthly oil prices"

What is a speculator? Most asset markets are subject to high unexplained volatility. Lots of debate about its source.

Prices may move frequently as speculators try to anticipate the future, but without speculation the movement would be larger when it occurs.

Expectations about the future are critical and big monthly moves are not because of chance or "speculators" -- changing fundamentals matter.
-see background information here

-see background information here

Poorly worded. Prices are driven by asset demands, not flows. Term "speculators" is misleading although technically accurate.

The price appears to fluctuate more vigorously than can be explained simply by changes in fundamentals.

Supply and demand.

It may play a role, but supply, demand and expectations of their future trends seem to dominate.
-see background information here
-see background information here