Not my area of expertise and so trying to dig up information on how this thing actually works. Has not made sense so far.
There is a lot of statistics on the EIA site where these weekly numbers come from but very little explanation of why and how.
For example, after weeks of declines in crude oil imports, the imports suddenly surged by 10% in the week 1/1 - 1/8. This in the face of increasing domestic production (though domestic oil is of a different type and not always a direct substitute for imports). But finished products inventory has been increasing for weeks, total crude oil inventory has been relatively flat.
So who makes the decision to suddenly increase imports by 10% and why? This is what led to to increased inventory numbers that is crashing the markets today and lowering oil prices. It is certainly not in the financial interests of refiners to do such errors or miscalculations in a falling price market, so why would that happen? Saudis/OPEC can output whatever they want but unless someone here decides to import it (and seemingly against their financial interests), the inventories should rise in the Middle East not in the US.
Not looking for tin foil hat theories but very little makes sense so far on how this thing actually works and what synthetic financial instruments if any may be in play that affects these numbers. I don't even know if EIA measures just physical amounts or also includes paper contracts without possession (in which case, it may be affected by futures trading strategies than just refiner demands).
If anyone here knows or is interested in helping collectively digging this thing out just out of curiosity, please do share.