CoStar Group CEO Andrew C Florance bought $2.49 million of company stock on August 4, 2026, acquiring 83,300 shares at $29.89 each in an open-market transaction. The trade was disclosed in a Form 4 filing with the Securities and Exchange Commission on August 5, just one day later.
The August purchase was the latest in a series of 2026 open-market buys by Florance. On February 27, he bought 55,720 shares at $44.52 per share, a $2,480,654 transaction. On May 1, he added 71,430 shares across two blocks: 68,330 shares at $35.17 and 3,100 shares at $35.82, for a combined $2,514,208. His four 2026 trades now total 210,450 shares at an aggregate cost of roughly $7.48 million. After the August purchase, Florance reported holding 1,806,165.03 shares.
Other insiders also acquired $CSGP stock on the open market this year. President Frederick G. Saint bought 20,000 shares at $45.33 on March 2, a $906,600 transaction. That same day director Rachel C Glaser bought 1,000 shares at $44.94, and on March 6 director Louise S Sams picked up 1,000 shares at $48.36. No insider has filed an open-market sale of $CSGP in 2026. The most recent insider sales occurred in November 2025, when Chief Accounting Officer Cynthia Cammett Cann sold 1,841 shares at $68.79 and director John W Hill sold 2,250 at $68.68. President Saint sold $CSGP shares above $90 during the summer of 2025.
The stock closed at $29.82 on August 4, trading between $29.35 and $30.07 during the day. Florance paid $29.89, near the top of that range. For comparison, $CSGP closed at $44.63 on February 27 and $34.72 on May 1, the dates of his earlier 2026 buys. After touching an intraday low of $25.89 on July 29, the stock recovered above $30 intraday by August 4.
Representatives Ro Khanna and Gilbert Cisneros, both California Democrats, disclosed several $CSGP transactions through STOCK Act filings over the past year. Their reported trades fell in the $1,001 to $15,000 range each, amounts substantially smaller than the multi-million-dollar insider purchases. Khanna’s most recent $CSGP trade was a purchase on May 27, 2026, disclosed June 9. Cisneros last reported a sale on April 14, 2026, disclosed May 8. The 2026 insider buying occurred as $CSGP shares declined sharply from their second-half 2025 levels, when the stock ranged from the low $70s in early June to above $93 in late July.