CoStar Group CEO Andrew Florance and other senior executives purchased thousands of company shares to signal confidence in the firm's current strategy.
The stock has declined 28% year-to-date as investors react to heavy spending on the Homes.com residential platform.
Activist hedge funds Third Point and D.E. Shaw are currently pressuring the company to scale back its residential market expansion.
CoStar shares rose more than 2% during Wednesday's trading session following the news of the insider purchases.