What happened

Speaking at the Future of Technology virtual conference hosted by KeyBanc Capital Markets today, Micron Technology (MU 2.92%) CFO David Zinsner laid out a conservative forecast for revenue over the next few quarters.

Micron shares are down 4.5% in response as of 1:40 p.m. EDT.

A glowing red stock chart arrow trending down

Image source: Getty Images.

So what

TheFly.com reports from the conference that Micron is guiding investors to expect $6 billion in revenue, plus or minus $250 million, in fiscal Q4. (Last quarter was Q3, by the way. By Micron's calendar, Q4 is the quarter we're in right now.) The good news is that $6 billion is actually a little bit ahead of consensus forecasts from Wall Street.   

But here's the bad news: Zinsner noted that Q4 has one more week in it this year than last. If you strip out revenue from that extra week to make the number more comparable to the same quarter last year, this year's Q4 sales actually look more like $5.6 billion.

Now what

Even that would be a 14% improvement over Micron's performance in last year's Q4, but it's only a 4% sequential improvement over Q3's $5.4 billion. Moreover, Zinsner says fiscal Q1 2021 should be in the $5.4 billion range as well -- versus the $5.8 billion in revenue that Wall Street wants to see.

Thus, the reason investors are selling Micron stock today: Q4 may look just fine. It may look downright terrific in comparison to last year's Q4. But if you look just one more quarter ahead, trouble may be brewing for Micron's sales.

And that's not what investors wanted to hear, at all.