Bambusa Therapeutics CEO receives 758K-share grant

The option award has a $16 exercise price, while restricted stock unit vesting depends on a certified share-price target and continued service.

Available on EDGAR 11/02/2026 - 04:02 PM EST Accepted by SEC EDGAR 11/02/2026 - 04:01 PM EST Learn about SEC filing dates

Rhea-AI Filing Summary

Shanshan Xu, Bambusa Therapeutics, Inc.'s Co-Founder, Chief Executive Officer, President and Chairperson, was granted 379,102 stock options and 758,204 restricted stock units on October 29, 2026. The options have a $16 per-share exercise price and expire October 28, 2036. Each restricted stock unit is a contingent right to receive one share of common stock.

The options vest over time, subject to continued service. The restricted stock units have a service and share-price condition for vesting.

Insider Trade Summary

Grant/Award: 1,137,306 shares

Grant/Award 2 txns

Insider Xu Shanshan

Role See remarks

Type	Security	Shares	Price	Value
Grant/Award	Stock Option (right to buy) F1	379,102	$0.00	$0.00
Grant/Award	Restricted Stock Units F2, F3	758,204	$0.00	$0.00

Holdings After Transaction: Stock Option (right to buy) — 379,102 contracts (Direct); Restricted Stock Units — 758,204 contracts (Direct)

Footnotes (3)

1. F1. Subject to the Reporting Person continuing to be a Service Provider (as defined in the Issuer's 2026 Equity Incentive Plan) through each applicable date, twenty five percent (25%) of the shares subject to the option shall vest on the one (1) year anniversary of the Vesting Commencement Date, and one forty-eighth (1/48th) of the shares subject to the option shall vest each month thereafter on the same day of the month as the Vesting Commencement Date (and if there is no corresponding day, on the last day of the month). "Vesting Commencement Date" shall mean October 29, 2026.
2. F2. Each restricted stock unit ("RSU") represents a contingent right to receive one share of the Issuer's Common Stock.
3. F3. Subject to the Reporting Person continuing to be a Service Provider (as defined in the Issuer's 2026 Equity Incentive Plan) through such applicable date, one hundred percent (100%) of the RSUs subject to the award shall vest upon the Administrator (as defined in the Issuer's 2026 Equity Incentive Plan) determining and certifying the achievement of the weighted average price of a share of the Issuer's common stock equals or exceeds $32 for any period of 30 consecutive trading days following April 1, 2027 and prior to April 1, 2030.

Key Figures

Stock options awarded: 379,102 options Exercise price: $16 per share Option expiration date: October 28, 2036 +4 more

7 metrics

Stock options awarded 379,102 options Granted October 29, 2026

Exercise price $16 per share Stock options granted October 29, 2026

Option expiration date October 28, 2036 Stock options granted October 29, 2026

Restricted stock units awarded 758,204 units Granted October 29, 2026

Initial option vesting 25% On the one-year anniversary of the October 29, 2026 vesting commencement date, subject to continued service

Subsequent option vesting 1/48 of the shares per month After the one-year anniversary, subject to continued service

Restricted stock unit share-price condition $32 for any period of 30 consecutive trading days After April 1, 2027, and before April 1, 2030; subject to continued service and administrator determination and certification

Key Terms

restricted stock unit, Vesting Commencement Date, Service Provider, weighted average price

4 terms

restricted stock unit financial

"Each restricted stock unit ("RSU") represents a contingent right"

A restricted stock unit is a promise from a company to give an employee shares of stock after certain conditions are met, like staying with the company for a set amount of time. It’s like earning a bonus that turns into company stock once you’ve proven your commitment, making it a way to motivate and reward employees.

Vesting Commencement Date technical

""Vesting Commencement Date" shall mean October 29, 2026."

The vesting commencement date is the starting point when an employee begins earning ownership rights to their promised benefits, such as stock options or retirement contributions. Think of it like the day a savings account is opened—only after this date do the benefits start to grow and become fully available over time. It matters to investors because it marks when the clock begins ticking toward full ownership, affecting the timing and value of these benefits.

Service Provider technical

"continuing to be a Service Provider"

weighted average price financial

"achievement of the weighted average price of a share"

Weighted average price is the average price of a security where each trade or component is counted according to its size, so bigger trades pull the average more than smaller ones. Think of it like calculating the average cost of a grocery haul where items you bought more of have greater influence on the final per-item cost. Investors use it to understand the true average price paid or received, judge execution quality, and compare trading performance against market movement.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What equity awards did BBTX CEO Shanshan Xu receive?

On October 29, 2026, Shanshan Xu was granted 379,102 stock options with a $16 per-share exercise price and 758,204 restricted stock units. Each restricted stock unit is a contingent right to receive one share of common stock.

What are the vesting conditions for Shanshan Xu's BBTX awards?

The options vest 25% on the one-year anniversary of October 29, 2026, then 1/48 monthly thereafter, subject to continued service. The restricted stock units vest 100% if, subject to continued service, the administrator determines and certifies that the weighted average share price equals or exceeds $32 for any period of 30 consecutive trading days after April 1, 2027, and before April 1, 2030.

AI-generated analysis. How Rhea-AI works. Not financial advice.

Form 4 Insider Transactions: What Each Field Means →

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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

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^*

Xu Shanshan

(Last) (First) (Middle)

C/O BAMBUSA THERAPEUTICS, INC.

22 BOSTON WHARF ROAD, FLOOR 7

(Street)

BOSTON MASSACHUSETTS 02210

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
Bambusa Therapeutics, Inc. [ BBTX ]

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

X	Director	X	10% Owner
X	Officer (give title below)		Other (specify below)
	See remarks

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
10/29/2026

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

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

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

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

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)	$16	10/29/2026		A		379,102		(1)	10/28/2036	Common Stock	379,102	$0	379,102	D
Restricted Stock Units	(2)	10/29/2026		A		758,204		(3)	(3)	Common Stock	758,204	$0	758,204	D

Explanation of Responses:

1. Subject to the Reporting Person continuing to be a Service Provider (as defined in the Issuer's 2026 Equity Incentive Plan) through each applicable date, twenty five percent (25%) of the shares subject to the option shall vest on the one (1) year anniversary of the Vesting Commencement Date, and one forty-eighth (1/48th) of the shares subject to the option shall vest each month thereafter on the same day of the month as the Vesting Commencement Date (and if there is no corresponding day, on the last day of the month). "Vesting Commencement Date" shall mean October 29, 2026.

2. Each restricted stock unit ("RSU") represents a contingent right to receive one share of the Issuer's Common Stock.

3. Subject to the Reporting Person continuing to be a Service Provider (as defined in the Issuer's 2026 Equity Incentive Plan) through such applicable date, one hundred percent (100%) of the RSUs subject to the award shall vest upon the Administrator (as defined in the Issuer's 2026 Equity Incentive Plan) determining and certifying the achievement of the weighted average price of a share of the Issuer's common stock equals or exceeds $32 for any period of 30 consecutive trading days following April 1, 2027 and prior to April 1, 2030.

Remarks:

Co-Founder, Chief Executive Officer, President, and Chairperson

	/s/ Jonathan I. Lieber, as attorney-in-fact	11/02/2026
	** 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.
* Form 4: SEC 1474 (03-26)