[z_CharlieMiller]

Since joining the site fairly recently I've begun studying the Wyckoff book by Pruden and am just now trying to put the new learning into practice. 

I've come upon a question that I don't see the book really answering, so I thought I'd put it out to the group for consideration/disucssion, and hopefully an answer. 

The stock is Ally Bank (ALLY), which I'd identified some time back as a possible short just based on Weinstein characteristics: The stock had broken the 30 week, the slope of the 30 week had been weakening for some time, and the 30 week was beginning at that time to look like it was going to roll over, which by now it has done. 

Since that that time the daily chart seems to have traced out a pattern with Wyckoff features I've named as best I could in the attachment (this is early days for me and Wyckoff so, feedback/comments on alternative interpretations most welcome). 

What I think I am seeing now is that the recent Sign of Weakness downtrend followed by a rally attempt that only made it about halfway up the trading range before heading south, I believe would make the peak of that failed attempt the Last Point of Supply, which I suspect would have been just the right place to open a short position.

My question has to do with estimating the size of the potential drop. I've attached my P&F view, taking 49 as LPS and estimating a width of 8 or 9 boxes, and thus estimating 41 or perhaps 40 as the near term ground floor of the elevator, with likely stops/bumps around 45 and 43.  Very much appreciate comments and suggestions along this line. Also I am using a daily P&F for this, and a get a slightly different answer (more like 43) using a weekly P&F and the weekly doesn't show the features as well. I'm supposing that daily is the correct one to use, but I don't know that. The daily P&F does at least harmonize the time scales between the P&F and the bar chart. 

Other thing I'd mention is that I became interested in this ticker as a possible short back before joining stockcharts.com and based on what I have learned using their user-friendly sector tools I might have eliminated it based on the emerging RS of the Banks sector. Of course, these things are never as crisp and clean as we'd like, but I still think this chart is going to be an interesting exercise as I'm learning Wyckoff and how to read/use a P&F chart. Appreciate comments, suggestion, discussion. 

Thanks, 
Charlie