CoStar Group, Inc. Announces Exercise of Underwriters’ Option to Purchase an Additional 343,511 Shares of Common Stock

WASHINGTON–(BUSINESS WIRE)–CoStar Group, Inc. (Nasdaq: CSGP) (“CoStar”) today announced that the underwriters have exercised their option to purchase an additional 343,511 shares of CoStar’s common stock at $655.00 per share, in addition to the 2,290,076 shares of CoStar common stock, which were purchased on May 20, 2020. Goldman Sachs & Co. LLC, J.P. Morgan, BofA Securities and Citigroup are acting as joint book-running managers for the offering. The sale of the overallotment shares is expected to close on March 28, 2020, subject to customary closing conditions. CoStar expects to use the net proceeds of the offering to fund all or a portion of the costs of any strategic acquisitions it determines to pursue in the future, to finance the growth of its business and for working capital and other general corporate purposes.

The shares are being offered pursuant to an effective shelf registration statement that has been filed with the Securities and Exchange Commission (“SEC”). A prospectus supplement related to the offering has been filed with the SEC and is available on the SEC’s website at http://www.sec.gov. Copies of the prospectus supplement and accompanying prospectus relating to the offering may be obtained from: Goldman Sachs & Co. LLC, Prospectus Department, 200 West Street, New York, NY 10282, telephone at (866) 471-2526, facsimile at (212) 902-9316 or by emailing prospectus-ny@ny.email.gs.com or J.P. Morgan Securities LLC, Attention: Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, NY 11717, by telephone at (866) 803-9204 or by email at prospectus-eq_fi@jpmchase.com.

This news release shall not constitute an offer to sell or the solicitation of an offer to buy, nor shall there be any sale of these securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction. The offering of these securities will be made only by means of the prospectus supplement and the accompanying prospectus.

About CoStar Group, Inc.

CoStar Group, Inc. (Nasdaq: CSGP) is the leading provider of commercial real estate information, analytics and online marketplaces. Founded in 1987, CoStar conducts expansive, ongoing research to produce and maintain the largest and most comprehensive database of commercial real estate information. Our suite of online services enables clients to analyze, interpret and gain unmatched insight on commercial property values, market conditions and current availabilities. Headquartered in Washington, DC, CoStar maintains offices throughout the U.S. and in Europe, Canada and Asia with a staff of over 4,200 worldwide, including the industry’s largest professional research organization.

Forward-looking statements

This news release contains “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Such statements include, but are not limited to, statements about CoStar’s plans, objectives, expectations and intentions and other statements including words such as “hope,” “anticipate,” “may,” “believe,” “expect,” “intend,” “will,” “should,” “plan,” “estimate,” “predict,” “continue” and “potential” or the negative of these terms or other comparable terminology. Such statements are estimates reflecting our judgment, beliefs and expectations, not guarantees of future performance. They are subject to a number of assumptions, risks and uncertainties that could cause actual results to differ materially from those expressed or implied in the forward-looking statements. More information about potential factors that could cause results or other outcomes to differ materially from those expressed or implied in the forward-looking statements can be found in CoStar’s Annual Report on Form 10-K for the year ended December 31, 2019, and CoStar’s Quarterly Report on Form 10-Q for the quarter ended March 31, 2020, each of which is filed with the SEC, including in the “Risk Factors” section of those filings, and the company’s other filings with the SEC available at the SEC’s website (www.sec.gov). CoStar assumes no obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.

Contacts

Investor Contacts:

Scott Wheeler

Chief Financial Officer

(202) 336-6920,

swheeler@costar.com

Sarah Spray

Vice President, Investor Relations

(202) 346 6394,

sspray@costar.com