[Form 4] 89bio, Inc. Insider Trading Activity

Rhea-AI Filing Summary

89bio (ETNB) CFO Ryan Martins reported merger-related equity transactions tied to the Roche acquisition. On October 30, 2025, a tender offer was completed and followed by a merger in which each common share was exchanged for $14.50 in cash plus one non-tradeable CVR with potential contingent payments of up to $6.00 per share, subject to the CVR Agreement.

Immediately prior to the effective time, previously granted performance-based RSUs vested and settled into 35,000 shares. All outstanding common shares were then exchanged for the offer consideration, and the reporting person showed 0 shares beneficially owned after the transaction. Stock options became fully vested; in general, in-the-money options received cash equal to intrinsic value plus a CVR per underlying share, options with exercise prices between $14.50 and $20.50 received a CVR per underlying share, and options at or above $20.50 were cancelled without consideration.

Insights

M&A and equity compensation analyst

Officer’s holdings converted per Roche deal at $14.50 + CVR.

The filing shows completion of Roche’s tender offer on October 30, 2025 with each 89bio share exchanged for $14.50 in cash plus one CVR with potential payments up to $6.00 per share. The CFO’s performance-based RSUs vested immediately prior to the merger and settled into 35,000 shares before being exchanged.

Options were fully vested at closing. In-the-money grants received cash equal to intrinsic value plus a CVR per underlying share. Grants with exercise prices between $14.50 and $20.50 received only a CVR per underlying share, and options at or above $20.50 were cancelled with no consideration.

After these transactions, the officer reported 0 shares beneficially owned. Actual value realization from CVRs depends on future milestone achievements under the CVR Agreement.

SEC Form 4

FORM 4

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
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

X

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

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Martins Ryan

(Last) (First) (Middle)

C/O 89BIO, INC.

655 MONTGOMERY STREET, SUITE 1500

(Street)

SAN FRANCISCO CA 94111

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
89bio, Inc. [ ETNB ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Financial Officer

3. Date of Earliest Transaction (Month/Day/Year)
10/30/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	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
Common Stock	10/30/2025		A		35,000(1)	A	$0	374,295	D
Common Stock	10/30/2025		U		374,295(2)(3)	D	(2)(3)	0	D

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 (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	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 (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (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: 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
Stock Option (Right to Buy)	$32.5	10/30/2025		D			47,500	(4)(5)(6)	02/14/2030	Common Stock	47,500	$0	0	D
Stock Option (Right to Buy)	$23.01	10/30/2025		D			57,500	(4)(5)(6)	02/05/2031	Common Stock	57,500	$0	0	D
Stock Option (Right to Buy)	$4.44	10/30/2025		D			48,102	(4)(5)(6)	02/16/2032	Common Stock	48,102	$0	0	D
Stock Option (Right to Buy)	$14.7	10/30/2025		D			110,000	(4)(5)(6)	02/09/2033	Common Stock	110,000	$0	0	D
Stock Option (Right to Buy)	$9.98	10/30/2025		D			175,000	(4)(5)(6)	02/01/2034	Common Stock	175,000	$0	0	D
Stock Option (Right to Buy)	$9.6	10/30/2025		D			300,000	(4)(5)(6)	02/01/2035	Common Stock	300,000	$0	0	D

Explanation of Responses:

1. Represents settlement by the Issuer of performance-based restricted stock units granted to the Reporting Person under the Company's Amended and Restated 2019 Equity Incentive Plan on September 9, 2022 and February 1, 2024, which vested as of immediately prior to and conditioned upon the occurrence of the effective time of the Merger (as defined below), pursuant to the Merger Agreement (as defined below).

2. Disposed of pursuant to the Agreement and Plan of Merger (the "Merger Agreement"), dated as of September 17, 2025, by and among 89bio, Inc. (the "Issuer"), Roche Holdings, Inc. ("Parent") and Bluefin Merger Subsidiary, Inc., a wholly owned subsidiary of Parent ("Merger Sub"). On October 30, 2025, Parent and Merger Sub completed a tender offer pursuant to the terms of the Merger Agreement for all outstanding shares of common stock of the Issuer (each, a "Share") for an offer price of (i) $14.50 per Share in cash, without interest (the "Closing Amount") less any required withholding taxes, plus (ii) one non-tradeable contingent value right (each, a "CVR") representing the right to receive certain contingent payments of up to an aggregate amount of $6.00 per Share, in cash, without interest less any required withholding taxes, upon the achievement of specified milestones on or prior to the applicable milestone outside dates, [continues to Footnote 3]

3. [continues from Footnote 2] subject to and in accordance with the terms of the Contingent Value Rights Agreement (the "CVR Agreement") (the Closing Amount plus one CVR, collectively, the "Offer Price"). Merger Sub thereafter merged with and into the Issuer, with the Issuer continuing as the surviving corporation and a wholly owned subsidiary of Parent (the "Merger"). At the effective time of the Merger, each issued and outstanding Share (other than any Excluded Shares (as such term is defined in the Merger Agreement)) was cancelled in exchange for the right to receive the Offer Price. In addition, as of immediately prior to and conditioned upon the occurrence of the effective time of the Merger, pursuant to the Merger Agreement, each outstanding restricted stock unit or performance-based restricted stock unit became fully vested and was cancelled in exchange for the right to receive the Offer Price.

4. As of immediately prior to and conditioned upon the occurrence of the effective time of the Merger, pursuant to the Merger Agreement, each outstanding option to purchase Shares (each, an "Option") became fully vested and exercisable, and to the extent not exercised prior to the effective time of the Merger, was cancelled and converted into the right to receive (i) an amount in cash (without interest and subject to deduction for any required withholding taxes) equal to the product of (A) an amount equal to the excess of the Closing Amount over the exercise price per Share with respect to such Option and (B) the number of Shares subject to such Option plus (ii) one CVR with respect to each Share subject to such Option (the "Option Consideration"); provided, however, that if the exercise price per Share of any Option was equal to or greater than the Closing Amount, but less than $20.50 (any such option, an "Out of the Money Option"), [continues to Footnote 5]

5. [Continues from Footnote 4] such Out of the Money Option was not entitled to any payment of the Closing Amount in respect thereof and each Out of the Money Option was converted into the right to receive the CVR included in the Option Consideration with respect to each Share underlying such Out of the Money Option and became entitled to receive, at each time a milestone payment becomes due and payable under the terms of the CVR Agreement, an amount in cash equal to the product of (i) the number of Shares subject to such Out of the Money Option, and (ii) the amount, if any, by which (A) the Closing Amount plus the applicable milestone payment plus any other milestone payment that previously became due and payable under the terms of the CVR Agreement exceeds (B) the exercise price per Share with respect to such Out of the Money Option plus the amounts, [continues to Footnote 6]

6. [Continues from Footnote 5] if any, paid to such Option holder with respect to such CVR in respect of any milestone payments that previously became due and payable under the terms of the CVR Agreement; provided further, that any Option with an exercise price that was equal to or greater than $20.50, was cancelled immediately prior to the effective time of the Merger without the receipt of any payment of the Closing Amount or CVR in respect thereof.

	/s/ Ryan A. Murr, as attorney-in-fact for Ryan Martins	10/30/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What did Roche pay per 89bio (ETNB) share in this transaction?

Each share was exchanged for $14.50 in cash plus one non-tradeable CVR with potential contingent payments up to $6.00 per share.

When was the 89bio (ETNB) tender offer completed?

The tender offer was completed on October 30, 2025, followed by a merger.

How were the CFO’s RSUs treated in the 89bio deal?

Performance-based RSUs vested immediately prior to the effective time and settled into 35,000 shares before being exchanged for the offer consideration.

What happened to 89bio stock options in the merger?

Options vested; in-the-money options received cash equal to intrinsic value plus a CVR per underlying share, certain out-of-the-money options received a CVR only, and options at or above $20.50 were cancelled with no consideration.

Did the reporting officer retain any 89bio shares after closing?

No. The filing shows 0 shares beneficially owned following the reported transactions.

What is the maximum potential CVR payment per 89bio share?

Up to an aggregate amount of $6.00 per share, subject to milestones under the CVR Agreement.