What happened

Shares of Apple (AAPL -0.71%) fell on Tuesday, as a respected investment firm sees substantial downside ahead for investors. As of 10:38 a.m. EDT, Apple's stock was down 3% after falling as much as 6.4% earlier in the day. 

So what 

Investment bank Goldman Sachs reiterated its sell rating on Apple's stock on Tuesday. Analyst Rod Hall believes the tech titan's shares could fall more than 30% to $80, as growth in Apple's services and wearables segments fail to offset slowing iPhone sales. 

A grizzly bear.

Goldman Sachs is one of the biggest Apple bears on Wall Street. Image source: Getty Images.

Hall argues that with its shares currently trading at more than 35 times consensus earnings estimates for 2020, Apple is priced at levels similar to Microsoft, which has stronger growth prospects. He also notes that Apple's stock has doubled even as Wall Street's 2021 earnings estimates for the company have fallen. 

Finally, Hall cites Intel -- which has seen its share price plunge nearly 30% since late January -- as a cautionary tale of just how far a large-cap tech stock can fall when it disappoints investors.

Now what

It should be noted that Apple's stock price rose more than 70% since Hall first placed a sell rating its shares back on April 16. So far, he's been quite wrong as to his price forecasts for Apple. His arguments are also a bit puzzling, as they come at a time when Apple is gearing up for what looks to be a powerful 5G-fueled iPhone upgrade cycle. Thus, investors may be better served by not adopting Hall's bearish view of Apple's stock, and perhaps even using the sell-off to pick up some shares at better prices, should they continue to decline further.