What happened

Shares of Koss (KOSS 2.83%), the headphone maker that saw its shares explode earlier this year thanks to a short squeeze driven by traders on Reddit's WallStreetBets board, were falling back down to earth today. 

After surging once again on attention from the same set of traders, the stock was falling today on no news, likely giving back gains after shares nearly doubled yesterday.

As of 3:19 p.m. EST, shares were down 16.5%.

An investor looking at a stock chart going up and down

Image source: Getty Images.

So what

What was notable about today's sell-off is that came even as GameStop (GME 1.50%), the most popular WallStreetBets stock, was mostly flat today. Meanwhile, shares of AMC Entertainment (AMC -0.73%), another favorite of that Reddit board, were up modestly after the movie theater operator reported earnings last night.

That seemed to signal some bifurcation in stocks that had long moved in tandem; Koss shares spiked back in January as GameStop shares soared and also caught tailwinds from the video game retailer in its second surge in recent weeks.

There was no specific reason for Koss' sell-off, and the stock was barely mentioned on the popular Reddit message board, but the slide today may signal that traders are rotating out of Koss and into other stocks.

Now what

Over the near term, Koss shares are likely to be driven by day traders, and continue to be volatile and unpredictable. Over the long term, however, the company's fundamentals will eventually control the stock's movement, and there's little to get excited about there. This is a slow-growth business that is on track to generate roughly $1 million in net income this year, making its $200 million valuation look unsustainable.

The stock is still up close to 1,000% from where it was in early January before the Reddit crowd piled into it, so it could have a long way to fall if the sell-off continues.