Inventory levels increased with a vengeance this week, shooting up 2.3% to 13,357 over last week:

About half of that increase was in the $200K-$300K price range in Sacramento County:

It is only a matter of time before the price-range trends start affecting overall asking prices. Although they have stabilized over the past month, median, average, and price-per-sqft asking in all four counties is at an almost 1 year low, with only Placer showing a modest increasing trend in average asking price:

Flipper inventory continues to rise in all four counties as well:

Though not as fast as overall inventory. Thus, flipper market share has stabilized:

Looking at flipper market share in Sacramento a little closer, a pattern is beginning to emerge on a rough, 60-day time scale:

I would only be speculating (no pun intended) if I tried to explain this phenomenon, but here goes:
We know that inventory cycles on rough 30, 60, and 90 day intervals, centering on the first of each month. This is due to the typical listing contract durations a seller agrees to with an agent, and tendency to list around the beginning of a month. (The "roughness" comes in when a listing expires during the middle of the week, and doesn’t get re-listed until the following weekend or after a holiday.) Combined, these two factors lead to a pattern like this:

with weekly increases and monthly drops. Now, logic would indicate that flippers would adhere to the same cycle. However, if that were the case, we would not see a pattern in the market-share trend tied to the inventory cycle that would differentiate flippers from the rest of the market. This means that a disproportionately large number of flippers are dropping off and re-listing with the MLS at the same time.
Here is where the speculation comes in. Ruling out the possibility of a vast flipper conspiracy where they all get together and decide when to list their properties, I would guess instead that a large fraction of these flipper houses are owned by a mere handful of individuals or companies. Could it be that more and more of these flipper houses are falling back to the banks, even if they are not selling for less than the previous sale price? What does that say about HELOCs or "sloppy second" loans?
Or is it possible that a large REIT got into the flipping game in Sacramento, and is now left holding the bag?
Please, feel free to speculate in the comments. I would love to find out what is underlying this trend.