Analysts keep dropping their forecasts for how many iPhones Apple will sell in 2016

Well-respected analyst Ming-Chi Kuo of KGI Securities has lowered his forecasts for iPhone shipments - days after another analyst also lowered their forecast for iPhones in 2016.

9to5Mac reports that KGI has outlined a worst-case scenario in which iPhone shipments in 2016 could fall below their 2014 level. That would be a nightmare for Apple.

This is becoming a trend: Raymond James analysts Tavis C. McCourt and Mike Koban published a research note on April 21 which lowered the expectation for iPhone units shipped in 2016 to 212 million.

The Raymond James note explains that "our most likely scenario remains that shares trade sideways until their core iPhone sales can regain some momentum."

Kuo's research note includes his argument for why he's expecting a drop in iPhone shipments. 9to5Mac reports that Kuo isn't positive about the ability of the iPhone SE and the upcoming iPhone 7 to retain Apple's iPhone growth.

And Kuo is a reliable indicator of what's coming next with iPhones - he has sources within the company's supply chain who give him the inside track.

Apple's stock price has had a rocky time in recent weeks, and the repeated estimation cuts from analysts isn't helping:

There's an ongoing argument that Apple has reached "peak iPhone." Towards the end of last year analysts started to predict that iPhone sales will drop in 2016 for the first time ever.

Most of those predictions come from examining the earnings reports of Apple's suppliers. If companies like Qualcomm and Dialog Semiconductor report weaker earnings, then chances are that Apple is lowering its orders for their chips.