Apple (AAPL) sold a record-breaking 5 million iPhone 5 handsets during the device’s debut weekend but despite a strong start, the sleek new smartphone has become Wall Street’s whipping boy in recent weeks. Following reports that Apple slashed iPhone 5 component orders in half due to weak demand, numerous institutions have cut their estimates on Apple’s performance in fiscal 2013 and 2014, often citing their own iPhone 5 checks when relaying the news to clients. Is this a case of stock manipulation as a number of Apple bloggers have suggested, or is there now enough smoke to assume there really is a fire?

Nomura on Tuesday became the latest in a long line of firms to cut its price target on Apple shares. Nomura analyst Stuart Jeffrey dropped his target to $530 from $660, again citing weak iPhone 5 demand and increased pressure on Apple’s margins.

“To reflect signs of weaker-than-expected iPhone 5 sales, we have cut unit estimates by 5% in FY13E and by 8% for FY14E,” the analyst wrote in a note to clients on Tuesday. “Our scenario analysis shows that if iPhone gross margins fall from a recent high of 55% (estimated) to 45%, EPS for FY14E and FY15E will likely peak at $46 to $48, with $4-5 downside if margins fall to 40% – the historic peak for mobile phone vendors. Our blended average fair value based on falling iPhone gross margins comes to $495 – $579 (ex / with excess cash), with potential downside to $400 and upside to $660.”

Adding to investors’ continued concerns are a half-dozen independent reports suggesting Apple plans to launch a new cheaper iPhone model later this year. The move would likely help Apple to better address emerging markets where it would finally be able to compete with low-end Android handsets, but it would also put a serious squeeze on Apple’s margins.

Apple is expected to report a huge holiday quarter next week, posting a quarterly profit somewhere in the ballpark of $13 billion. We could still be in for a bloodbath if Apple misses Wall Street’s consensus for the third consecutive quarter though, and Apple’s fiscal Q1 iPhone shipments will be under the spotlight like never before.