What happened

Novavax (NASDAQ:NVAX) stumbled on Monday, with the stock declining by 4.4%. The key reason for the coronavirus vaccine developer's decline seems to be a set of company stock sales reported for top insiders earlier in the day.

So what

Citing regulatory filings, Reuters reported that the biotech's CEO, Stanley Erck, and "three lieutenants" it did not name have sold around $46 million worth of Novavax stock since the beginning of 2020.

Stethoscope atop $100 bills and pennies.

Image source: Getty Images.

In 2020, Erck sold $8.7 million worth of stock. According to Reuters, this was over 20% of his vested stake in the company. That amount was also nearly four times the $2.2 million he unloaded in the preceding five years.  

While Novavax is actively developing a coronavirus vaccine -- NVX-CoV2373 -- it is still in clinical testing. Several rival vaccines have already been authorized for use by major regulators.

Reuters quoted an unnamed spokeswoman for the biotech implying that these sales are not untoward. She said the company's leaders "continue to hold substantial personal and professional interest in Novavax's success as well as a financial one."

Now what

Corporate insiders sell stock all the time to bolster their liquidity. Also, even with recent pullbacks, Novavax's shares have risen by nearly 2,900% over the past year, so they are far pricier than they used to be. Still, it's not really a good look for the company when its vaccine candidate hasn't yet made it to market.