<<Pfizer in 2007 bought back in the area of $18 Billion in stock alone, so I don't see them using it in transactions as bogus.>>
Your point, I thought, was that there was something notable about PFE's decline in market cap (shares outstanding times value), as opposed to a mere decline in their price per share. The share buybacks you mention would, of course, reduce market cap. I think that if f you take your figure for PFE acquisitions, adjust for the PFE shares bought back for cash, and exclude the portion of the WYE acquisition that was for cash, you will find that the two declines are exactly the same. It is still a remarkable decline, that's for sure.
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