Personalis Announces Pricing of Public Offering of Common Stock

Personalis, Inc. (Nasdaq: PSNL), a leader in advanced genomics for population sequencing and cancer, today announced the pricing of its previously announced underwritten public offering of 3,950,000 shares of its common stock at a price to the public of $38.00 per share. Gross proceeds to Personalis from the offering are expected to be $150.1 million, before deducting underwriting discounts and commissions and estimated offering expenses.

In addition, the underwriters have been granted a 30-day option to purchase up to an additional 592,500 shares of common stock from Personalis on the same terms and conditions.

Morgan Stanley, BofA Securities, Citigroup and Cowen are acting as joint book-running managers. BTIG is acting as co-manager.

A shelf registration statement relating to the shares being sold in this offering was filed with the U.S. Securities and Exchange Commission on December 30, 2020, and was declared effective on January 8, 2021. A preliminary prospectus supplement and accompanying prospectus relating to the offering was filed with the SEC and are available for free on the SEC's website located at http://www.sec.gov. When available, electronic copies of the final prospectus supplement and accompanying prospectus relating to the offering may be obtained from Morgan Stanley & Co. LLC, Attention: Prospectus Department, 180 Varick Street, 2^nd Floor, New York, NY 10014; BofA Securities, Attention: Prospectus Department, NC1?004?03?43, 200 North College Street, 3rd floor, Charlotte, NC 28255?0001, or by emailing [email protected]; Citigroup Global Markets Inc., c/o Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, NY 11717, or by telephone at 1-800-831-9146; or Cowen and Company, LLC, c/o Broadridge Financial Solutions, Attention: Prospectus Department, 1155 Long Island Avenue, Edgewood, NY 11717, telephone: 1-833-297-2926.

This press 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.

About Personalis, Inc.

Personalis, Inc. is a leader in population sequencing and cancer genomics, with a focus on data, scale, efficiency and quality. Personalis operates one of the largest sequencing programs globally and is currently the sole sequencing provider to the U.S. Department of Veterans Affairs Million Veterans Program. In oncology, Personalis is transforming the development of next-generation therapies by providing more comprehensive molecular data about each patient's cancer and immune response. The Personalis^® ImmunoID NeXT Platform^® is designed to adapt to the complex and evolving understanding of cancer, providing its biopharmaceutical customers with information on all of the approximately 20,000 human genes, together with the immune system, from a single tissue or blood sample. The Personalis^® Clinical Laboratory is GxP aligned as well as CLIA'88-certified and CAP-accredited.

Forward-Looking Statements

This press release contains forward-looking statements, including statements relating to Personalis' expectations regarding the underwritten public offering. These statements are subject to significant risks and uncertainties and actual results could differ materially from those projected. Personalis cautions investors not to place undue reliance on the forward-looking statements contained in this release. These risks and uncertainties include, without limitation, the fact that completion of the underwritten public offering is subject to the satisfaction of customary closing conditions. Risks and uncertainties relating to Personalis and its business can be found in the "Risk Factors" sections of Personalis' Form 10-Q for the quarter ended September 30, 2020, filed with the SEC on November 5, 2020, the shelf registration statement filed with the SEC on December 30, 2020, the preliminary prospectus supplement related to the public offering filed with the SEC on January 26, 2021, and the final prospectus supplement related to the public offering to be filed with the SEC on or about January 27, 2021. Personalis undertakes no duty or obligation to update any forward-looking statements contained in this release as a result of new information, future events or changes in Personalis' expectations, except as required by law.