I did a great deal of rounding and guesswork, and there is great potential for human error in this work.   Moreover, as we all know, the bids and asks we see on AStocks' screen are not necessarily the actual best bids or best offers, etc, etc, etc.   For example, when CRTC was the only offer at a price and stock traded at that price, I assumed the seller was CRTC.  If CRTC was sharing the ask with other market makers (usually 1 other, sometimes as many as 4 others at the same price) I assumed that CRTC participated 1/3 of the time as a seller.
However, I believe I can show that CRTC is an effective blocker and supplier of downward pressure on the stock in recent weeks, far in excess of the actual shares being sold by CRTC.
Background: I noted recently that CRTC, who spent most of the summer on the BID side of our market as a buyer, recently began showing up regularly on the ASK side as a seller.
I reviewed the daily videos prepared by AStocks and took notes on what I saw.    It appears that on October 20 CRTC first appeared with stock for sale, and they have participated almost daily since then, for most of the trading day.
   Total Trading   Minutes CRTC    Shares Traded   Minutes CRTC        Shares Traded    Total
      Minutes        Low Bid Alone   At Ask Price   Low Bid w/ Others    At Ask Price     Volume
10/20   390       30        100       60        100      129,000
10/21   390      100       2200      170       2800       89,000    
10/22     390        0          0        40        100       49,000
10/23   390        0          0       30          0       86,000       
10/24   390        0          0      240       2200       39,000
10/27   390      110      30800        0          0      126,000
10/28   390       30        100      190      27100      129,000
10/29   390        0          0      320          0       35,000
10/30   390        0          0        0          0       48,000
10/31   390        0          0        0          0       42,000
11/03   390        -          -        -          -      281,000
11/04   390       10      12000       50      13000      449,000
11/05   390       150      56500      150      33800      231,000
11/06   390       20       1200      120       3300       92,000
11/07   390        0          0        0          0       85,000
11/10   390        -          -        -          -      247,000
11/11   390        0          0      280       9100       33,000
11/12   390        0          0      300      12300      306,000
11/13   390       10        500       60       14000      567,000
11/14   390        0          0        0          0      257,000
Total Trading Minutes: 20 days:  7,800
Trading Minutes on 18 days CRTC participated:  7,000
Approx. Minutes CRTC was offering stock for sale:  6,500  = 93% of the time
Approx. Minutes CRTC had lowest ask price by itself:  460  = 7% of the time
Approx. Minutes CRTC shared lowest ask along with others:  2,010  = 29% of the time
Approx. # shares sold by CRTC in last 20 days:  103,400 + (1/3 of 117,800) = 142,600 shares sold
Summary Points:
1.  CRTC appeared as a seller on October 20 and has been selling 18 of the last 20 days.
2.  On the days it was trading, CRTC has shown stock for sale about 93% of the time.
3.  On the days it was trading, CRTC had the lowest ask price only 36% of the time.
4.  Over the last 20 days, I believe CRTC sold approximately 142,600 shares of stock.
5.  That 142,600 shares represented just 4% of the 3,220,00 shares traded in last 20 days.
So, why is any of this important or interesting?
If you subscribe to the theory that the prolonged slippage in WMIH's stock price is not as much due to knowledgable selling as it is due to frightened selling to knowledgable buyers, then you can take my post and do some (8-BALLing) with my results.
Here are a few things I take as givens:
1.  CRTC knows more about the WMIH situation than I do.  Kevin Starke, their analyst following our company, goes back to pre-bankruptcy days.
2.  CRTC spent all summer supporting the stock price and buying shares on a daily basis.
Then, I start 8-balling:
1.  If CRTC really wanted to sell their WMIH position, is this how they would do it?  Would you show up every day with an offering of stock, knowing full well that just your presence on the sell side sends a 'sell' signal to people watching the stock closely.  No, you would be much more secretive about it.
2.  Surely CRTC has more than 142,600 shares to sell (which is the approximate number I believe they sold in the last four weeks).  They probably own millions of shares.  At this rate it could take them years to sell out their position.  They know all the major players in the stock - they could pick up the phone and quietly do a large transaction(s) and be done with it.
3.  So, if CRTC isn't really serious about selling shares, why go through this excercise at all?  Why waste the time and energy posting stock for sale each day, juggling the price around many times each session, never quite selling shares, just keeping a lid on things?  
4.  What if CRTC is playing both sides of the market, working as a buyer as well?  Every trading day we see shares trade between AStock's bid and asked prices, and we never can figure out who is buying those shares so secretly.
5.  Perhaps CRTC is trying to 'shake shares loose'.  It isn't costing them many shares - they have only sold around 142,600 shares by my estimation - they could easily have bought 1,000,000 shares of more at the same time on the bid side of the market as retail shareholders got frightened and sold.  Sometimes CRTC appears as a bidder, but they could be completing trades without showing up on the L2 screens.