What happened

Shares of online coupon-hawker Groupon (GRPN -0.61%) tumbled as much as 10% in Tuesday trading before recovering just a bit to close the day down 9.1%.

You can blame Goldman Sachs for that.

Glowing red arrow trending down

Image source: Getty Images.

So what

Goldman downgraded the stock, saying in a note Tuesday morning that Groupon's customer base has shrunk for seven straight quarters, and that Goldman is finally throwing in the towel.  

Continued macroeconomic challenges, Goldman said, are going to weigh on billings and revenue, and will probably depress gross profit margins in the 2020 to 2021 period. And since Groupon is already unprofitable, that doesn't bode well for earnings growth -- or for the stock.  

Now what

According to Goldman Sachs, Groupon is only worth about $2.40 per share, and for that reason, the analyst thinks it's a sell. Investors dutifully complied and sold it off today, leaving the stock at $2.39 per share.