BTIF analyst Walter Piecyk tells clients in a note that he’s downgraded Apple stock from “buy” to “neutral.” Why? According to “Business Insider” (http://macte.ch/mSasr), here are the key points behind the Piecky’s reasoning:

° Apple will have another blowout quarter. Revenue will be US$40 billion for the second quarter vs. current estimates of $36 billion. But that’s where the good news ends.

° 2012 will be the year that the wireless carriers fight back against having their margins constantly squeezed. Specifically, they say that new new policies (especially from AT&T) will stunt the pace of product upgrades, depriving Apple of sales.

° So, in the third quarter, there will be a sequential decline in iPhone sales, and revenue will come in $1 billion below the current consensus.