What happened

Shares of Ziopharm Oncology (TCRT -2.68%), jumped more than 30% on Tuesday. Shares of the clinical-stage biopharmaceutical company finished Thursday up around 18% from their closing price last Friday. While the company's been quiet, investors were highly encouraged by a handful of insider stock purchases.

So what 

Last Friday afternoon, just before Labor Day weekend, Ziopharm disclosed to the Securities and Exchange Commission four direct stock purchases from company insiders. James Huang, a financier of several lucrative life-science ventures including Legend Biotech, raised his stake from a little over 8,000 shares to around 108,000 shares. One of the company's largest shareholders, Robert Postma, bought 75,000 shares pushing his total Ziopharm holdings past 5.45 million shares.

A person in a coffee shop looking at a laptop.

Image source: Getty Images.

Kevin Boyle, who became CEO in August, wasn't one of the insiders who disclosed a big purchase on Sept. 3. That's probably because the company gave him 875,000 shares when he was appointed to the lead role on Aug. 30.

Now what

Insiders also happen to be people with bills to pay and luxuries to acquire. Investors need to remember that insider selling can mean lots of things that are mostly innocuous. Direct purchases like these, though, generally don't happen unless insiders expect the price to rise. 

At his former position as CEO of Kuur Therapeutics, Boyle led the company through a successful transformation that ended with a $185 million acquisition by Athenex this May. It looks like the board members who hired Boyle are confident about his ability to try Ziopharm around, too. 

The company's CD19-directed cellular therapy candidate started a trial in Taiwan this March, but it's on pause while the company refines its manufacturing process. With a clinical-stage pipeline collecting dust at the moment, Boyle has his work cut out for him.