What happened

Shares of Petmed Express (PETS 2.40%) were soaring today, riding the surge in meme stocks that was led by AMC Entertainment, whose shares nearly doubled today. Petmed Express wasn't far behind as shares of the online pet pharmacy finished up 58.4%.

So what

The online pet pharmacy seemed to benefit from the same interest from investors on Reddit's WallStreetBets forum and other online platforms who were looking to execute a short squeeze, though PetMed Express wasn't specifically mentioned on WallStreetBets. As of May 13, 35% of the stock's float was sold short, meaning a significant number of investors were betting that the stock would fall. 

A beagle dog looking up.

Image source: Getty Images.

On an extremely high volume day when more than 10 million shares changed hands, compared to an average of less than 500,000, short-sellers may have rushed back in to close out their bets to avoid losing money as the stock soared over the course of the trading session.

Today's pop wasn't a total surprise as Petmed Express surged in late January alongside other meme stocks like Gamestop and AMC Entertainment, gaining 68% in just three days. However, it gave back most of those gains soon after.

Now what

As a business, Petmed Express has seen middling results in recent years with its top line steadily growing in the single digits. In fiscal 2021, which ended on March 31, revenue grew 8.8% to $309.2 million and earnings per share rose 18% to $1.52. 

Today's gain was an anomaly, and it's unclear if the stock will fade again like it did in January, but AMC's recent surge shows that the short-squeeze pops we saw earlier in the year can happen at any moment.