Guardant Health Announces Proposed Public Offering of Common Stock

Guardant Health, Inc. (Nasdaq:GH), a leading precision oncology company, today announced that it has commenced an underwritten public offering of $250.0 million of its common stock. In addition, Guardant Health intends to grant the underwriters a 30-day option to purchase up to $37.5 million of its common stock at the public offering price, less underwriting discounts and commissions. All of the shares of common stock in this offering will be sold by Guardant Health. The proposed offering is subject to market and other conditions, and there can be no assurance as to whether or when the proposed offering may be completed, or as to the actual size or terms of the proposed offering.

J.P. Morgan, Goldman Sachs & Co. LLC, TD Cowen and SVB Securities are acting as joint book-running managers for the proposed offering.

The shares of common stock are being offered by Guardant Health pursuant to an automatic shelf registration statement on Form S-3 that was previously filed with the U.S. Securities and Exchange Commission, or the SEC, and automatically became effective upon filing. A preliminary prospectus supplement and accompanying prospectus relating to and describing the terms of the proposed offering has been filed with the SEC and is available on the SEC's website at www.sec.gov.

Copies of the preliminary prospectus supplement and accompanying prospectus may be obtained by contacting:

J.P. Morgan Securities LLC
c/o Broadridge Financial Solutions
1155 Long Island Avenue, Edgewood, NY 11717
Telephone: (866) 803-9204, or email: [email protected];

Goldman Sachs & Co. LLC
Attention: Prospectus Department
200 West Street, New York, NY 10282
Telephone: (866) 471-2526, or email: [email protected];

Cowen and Company, LLC
599 Lexington Avenue, New York, NY 10022
Telephone: (833) 297-2926, or email: [email protected];

SVB Securities LLC
Attention: Syndicate Department
53 State Street, 40^th Floor, Boston, MA 02109
Telephone: (800) 808-7525, ext. 6105, or email: [email protected].

This press release shall not constitute an offer to sell or a solicitation of an offer to buy these securities, nor shall there be any sale of these securities in any state or other jurisdiction in which such offer, solicitation or sale would be unlawful prior to the registration or qualification under the securities laws of any such state or other jurisdiction.

About Guardant Health

Guardant Health is a leading precision oncology company focused on helping conquer cancer globally through use of its proprietary tests, vast data sets and advanced analytics. The Guardant Health oncology platform leverages capabilities to drive commercial adoption, improve patient clinical outcomes and lower healthcare costs across all stages of the cancer care continuum. Guardant Health has commercially launched Guardant360^®, Guardant360 CDx, Guardant360 TissueNexttm, Guardant360 Responsetm, and GuardantINFINITYtm tests for advanced-stage cancer, and Guardant Revealtm for early-stage cancer. The Guardant Health screening portfolio, including the commercially launched Shieldtm test, aims to address the needs of individuals eligible for cancer screening.

Forward Looking Statements

This press release contains forward-looking statements. All statements other than statements of historical facts contained herein, including without limitation statements regarding the completion, timing and size of the proposed public offering and the grant to the underwriters of an option to purchase additional shares are forward-looking statements reflecting the current beliefs and expectations of Guardant Health's management made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Forward-looking statements represent Guardant Health's current expectations regarding future events and are subject to known and unknown risks and uncertainties that could cause actual results to differ materially from those implied by the forward-looking statements. Among those risks and uncertainties are market conditions, including market interest rates, the trading price and volatility of Guardant Health's common stock, and risks relating to Guardant Health's business, including those risks described in periodic reports that Guardant Health files from time to time with the SEC, as well as the preliminary prospectus supplement and accompanying prospectus relating to the proposed offering. The forward-looking statements included in this press release speak only as of the date of this press release, and Guardant Health does not undertake to update the statements included in this press release for subsequent developments, except as may be required by law.