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Morgan Stanley isn't the only bank that's scared Apple won't be able to ship as many iPhones as originally predicted. Several additional companies have come forward with new research suggesting that early estimates might have been a bit too bullish.

Bank of America, Raymond James and Baird Equity all recently cut estimates, according to information received by Reuters. BofA now expects Apple will sell 220 million units in FY2016 instead of 230 million units, Raymond James adjusted its figures from 229 million units to 224 million units, Baird slashed its unit sales from 243.8 million units to 234.7 million units.

By comparison, Apple sold about 230 million iPhones in 2015, including 74M units in Q1, 61 million units in Q2, 47 million units in Q3 and 48 million units in Q4, all of which represented record quarters. Those estimates, however, suggest Apple's sales – while still rather astounding – might not crush records as they have in the past. Baird, it seems, is the most bullish of all with just a small expectation for increased sales.

The estimates were all revised following what seems to be "lackluster expectations at Apple suppliers," according to Reuters. There are a number of reasons why sales might be down, and Morgan Stanley recently suggested the problem might stem from "higher prices in international markets and maturing smartphone penetration in developed markets." In other words, there's some fear about growth in markets like the U.S. where folks already have smartphones and might not upgrade, and Apple's ability to compete in markets where there are lower priced smartphones.

As we mentioned earlier this week, though, Apple's secret weapon to keep iPhone sales up might be its rumored new 4-inch iPhone 6c. It's possible that could serve as a double-edged sword, catering to users who want smaller screens in developed smartphone markets, in addition to folks in emerging market who can't afford the price of more expensive iPhones.