The Numbers Game: Inside Crude Oil

NEW YORK (TheStreet) -- Every day, a gusher of economic data comes pouring out from one source or another.

Unemployment figures, manufacturing numbers, retail sales, consumer-confidence, gross-domestic product, spending estimates, orders for durable goods. This dizzying swath can be deep and confusing. Preliminary numbers are reported, only to be revised weeks later. Meanwhile, the markets rise and fall on it all.

Then there is the fairly simple question that two groups try to answer each week: How much oil exists in U.S. inventories?

The attempt is hardly an academic exercise -- that is, of course, if you subscribe to the belief that oil prices are actually determined by supply and demand.

The Energy Department's own Energy Information Administration typically releases inventory and production statistics for the prior week on Wednesday mornings. The trade industry's own American Petroleum Institute usually release their numbers on Tuesday afternoons.

Then, there's the weekly routine: Figures come out. Investors digest the numbers and trade on them. Crude futures immediately bound up or fall off in the immediate aftermath. Move on. Rinse. Repeat.

But, every so often, you have days like last week, when the EIA reported a 4.7 million barrel drop in oil inventories compared to the API's own showing of 631,000 barrel increase.

That's when this comment trickled in from a reader:

"Were you totally surprised about the huge disconnect between EIA and API numbers today? I was ... does anyone have any thoughts on that?" -- TradingNymph