Sec Form 3 Filing - VIKING GLOBAL INVESTORS LP @ RayzeBio, Inc. - 2023-09-14

FORM 3 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person VIKING GLOBAL INVESTORS LP 2. Issuer Name and Ticker or Trading Symbol RayzeBio, Inc. [ RYZB] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 600 WASHINGTON BLVD., FLOOR 11 3. Date of Earliest Transaction (MM/DD/YY) 09/14/2023 (Street) STAMFORD, CT06901 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Series B Convertible Preferred Stock ( 1 ) ( 1 ) ( 1 ) Common Stock 864,509 I See Explanation of Responses ( 4 ) ( 5 ) ( 6 ) ( 8 ) Series C Convertible Preferred Stock ( 2 ) ( 2 ) ( 2 ) Common Stock 494,687 I See Explanation of Responses ( 4 ) ( 5 ) ( 6 ) ( 8 ) Series D Convertible Preferred Stock ( 3 ) ( 3 ) ( 3 ) Common Stock 2,609,392 I See Explanation of Responses ( 4 ) ( 5 ) ( 6 ) ( 8 ) Series D Convertible Preferred Stock ( 3 ) ( 3 ) ( 3 ) Common Stock 1,285,223 I See Explanation of Responses ( 4 ) ( 5 ) ( 7 ) ( 8 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other VIKING GLOBAL INVESTORS LP 600 WASHINGTON BLVD. FLOOR 11 STAMFORD, CT06901 X Viking Global Opportunities Parent GP LLC 600 WASHINGTON BLVD. FLOOR 11 STAMFORD, CT06901 X Viking Global Opportunities GP LLC 600 WASHINGTON BLVD. FLOOR 11 STAMFORD, CT06901 X Viking Global Opportunities Portfolio GP LLC 600 WASHINGTON BLVD. FLOOR 11 STAMFORD, CT06901 X Viking Global Opportunities Illiquid Investments Sub-Master LP 600 WASHINGTON BLVD. FLOOR 11 STAMFORD, CT06901 X HALVORSEN OLE ANDREAS 600 WASHINGTON BLVD. FLOOR 11 STAMFORD, CT06901 X Ott David C. 600 WASHINGTON BLVD. FLOOR 11 STAMFORD, CT06901 X Shabet Rose Sharon 600 WASHINGTON BLVD. FLOOR 11 STAMFORD, CT06901 X Signatures /s/ Scott M. Hendler signing on behalf of O. Andreas Halvorsen (9)(10) 09/14/2023 Signature of Reporting Person Date /s/ Scott M. Hendler signing on behalf of David C. Ott (9)(10) 09/14/2023 Signature of Reporting Person Date /s/ Scott M. Hendler signing on behalf of Rose S. Shabet (9)(10) 09/14/2023 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Each share of Series B Convertible Preferred Stock (the "Series B Preferred Stock") is convertible into shares of Common Stock of the Issuer on a one-for-one basis. Upon the closing of the Issuer's initial public offering, the Series B Preferred Stock will convert into the number of shares of Common Stock of the Issuer shown in column 3. The Series B Preferred Stock has no expiration date. ( 2 )Each share of Series C Convertible Preferred Stock (the "Series C Preferred Stock") is convertible into shares of Common Stock of the Issuer on a one-for-1.14443753806379 basis. Upon the closing of the Issuer's initial public offering, the Series C Preferred Stock will convert into the number of shares of Common Stock of the Issuer shown in column 3. The Series C Preferred Stock has no expiration date. ( 3 )Each share of Series D Convertible Preferred Stock (the "Series D Preferred Stock") is convertible into shares of Common Stock of the Issuer on a one-for-one basis. Upon the closing of the Issuer's initial public offering, the Series D Preferred Stock will convert into the number of shares of Common Stock of the Issuer shown in column 3. The Series D Preferred Stock has no expiration date. ( 4 )Andreas Halvorsen, David C. Ott and Rose S. Shabet are Executive Committee members of certain management entities, including Viking Global Partners LLC, the general partner of Viking Global Investors LP ("VGI"), and Viking Global Opportunities Parent GP LLC ("Opportunities Parent"), the sole member of Viking Global Opportunities GP LLC ("Opportunities GP"), the sole member of Viking Global Opportunities Portfolio GP LLC ("Opportunities Portfolio GP"), the general partner of Viking Global Opportunities Illiquid Investments Sub-Master LP ("Opportunities Fund"). Opportunities Parent is also the sole member of Viking Global Opportunities Drawdown GP LLC ("VGOD GP"), the sole member of Viking Global Opportunities Drawdown Portfolio GP LLC ("VGOD Portfolio GP"), the general partner of Viking Global Opportunities Drawdown (Aggregator) LP ("VGOD"). ( 5 )VGI provides managerial services to various investment funds and vehicles, including Opportunities Fund and VGOD. VGI, Opportunities Parent, Opportunities GP, Opportunities Portfolio GP, Opportunities Fund, VGOD GP, VGOD Portfolio GP, VGOD, Mr. Halvorsen, Mr. Ott and Ms. Shabet are, collectively, the "Reporting Persons". Each of VGI, Opportunities Parent, Mr. Halvorsen, Mr. Ott and Ms. Shabet may be deemed to beneficially own all of the securities reported on this form. ( 6 )These securities are held directly by Opportunities Fund. Because of the relationship between Opportunities Portfolio GP, Opportunities GP, Opportunities Parent and Opportunities Fund, each of Opportunities Portfolio GP, Opportunities GP and Opportunities Parent may be deemed to beneficially own the securities held directly by Opportunities Fund. ( 7 )These securities are held directly by VGOD. Because of the relationship between VGOD Portfolio GP, VGOD GP, Opportunities Parent and VGOD, each of VGOD Portfolio GP, VGOD GP and Opportunities Parent may be deemed to beneficially own the securities held directly by VGOD. ( 8 )The Reporting Persons disclaim beneficial ownership of these securities except to the extent of their pecuniary interest therein, and the inclusion of these securities in this report shall not be deemed an admission of beneficial ownership of the reported securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), or for any other purpose.

Remarks: (9) The Reporting Persons are jointly filing this Form 3 pursuant to Rule 16a-3(j) under the Exchange Act. Because no more than 10 reporting persons can file any one Form 3 through the SEC's EDGAR system, VGOD GP, VGOD Portfolio GP and VGOD have jointly filed with the other Reporting Persons on a separate Form 3 filing submitted on the same day hereof. (10) Scott M. Hendler is signing on behalf of Mr. Halvorsen, Mr. Ott and Ms. Shabet, each individually and as an Executive Committee Member of VIKING GLOBAL PARTNERS LLC, on behalf of VIKING GLOBAL INVESTORS LP, and as an Executive Committee Member of VIKING GLOBAL OPPORTUNITIES PARENT GP LLC, on behalf of itself and VIKING GLOBAL OPPORTUNITIES GP LLC, VIKING GLOBAL OPPORTUNITIES PORTFOLIO GP LLC and VIKING GLOBAL OPPORTUNITIES ILLIQUID INVESTMENTS SUB-MASTER LP, pursuant to authorization and designation letters dated February 9, 2021, which were filed with the Securities and Exchange Commission on June 7, 2021.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by m ore than one reporting person, see Instruction 4(b)(v).

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