DESMARAIS MICHAEL J 4

What Happened

• Michael J. Desmarais, Chief Human Resources Officer of CoStar Group (CSGP), disposed of 2,873 shares on 2026-03-15 as payment of an exercise price or tax liability. The reported per-share value was $43.63, for a total of $125,349.
• This was a share-surrender (tax withholding) disposition rather than an open-market sale or a cash purchase.

Key Details

• Transaction date: 2026-03-15
• Price used: $43.63 per share (footnote: Nasdaq closing price on March 13, 2026)
• Shares surrendered/disposed: 2,873; aggregate value: $125,349
• Transaction code: F — payment of exercise price or tax liability (share withholding)
• Shares owned after the transaction: not specified in the provided filing
• Filing: Form 4 dated 2026-03-17; appears to be filed within the typical Section 16 timeframe

Context

• This type of transaction is commonly a tax-withholding event tied to option exercises or vesting of equity awards. It reflects using company shares to satisfy tax obligations and is routine; it does not necessarily indicate a buy/sell signal about the insider’s view of the stock.