Ribbon (RBBN) SVP exercises 37,500 RSUs; 14,756 shares withheld

Filing Impact

(Neutral)

Filing Sentiment

(Neutral)

Form Type

Rhea-AI Filing Summary

Ribbon Communications SVP, Deputy CFO and CAO Eric S. Marmurek exercised restricted stock units and settled related taxes in shares. On April 15, 2026, he exercised 37,500 Restricted Stock Units (each RSU representing a contingent right to one common share) into 37,500 shares of common stock. In connection with this vesting, 14,756 shares were withheld by the company at $2.48 per share to satisfy tax withholding obligations, rather than sold in the open market. These RSUs were originally issued on October 15, 2024, with remaining RSUs scheduled to vest on October 15, 2026. After these transactions, Marmurek directly holds 449,807 shares of Ribbon common stock, reflecting a routine compensation-related event.

Insider Trade Summary

37,500 shares exercised/converted

Mixed 3 txns

Insider Marmurek Eric S

Role SVP, Deputy CFO and CAO

Type	Security	Shares	Price	Value
Exercise	Restricted Stock Units (RSUs)	37,500	$0.00	--
Exercise	Common Stock	37,500	$0.00	--
Tax Withholding	Common Stock	14,756	$2.48	$37K

Holdings After Transaction: Restricted Stock Units (RSUs) — 37,500 shares (Direct); Common Stock — 464,563 shares (Direct)

Footnotes (1)

Eash RSU represents a contingent right to receive one share of the Registrant's common stock. Reflects shares of common stock withheld by the Registrant to satisfy tax withholding obligations in connection with the vesting. The RSUs were issued on October 15, 2024. The remaining RSUs vest on October 15, 2026.

Key Figures

RSUs exercised: 37,500 units Shares withheld for taxes: 14,756 shares Tax withholding reference price: $2.48 per share +4 more

7 metrics

RSUs exercised 37,500 units RSUs converted to common stock on April 15, 2026

Shares withheld for taxes 14,756 shares Common stock withheld at $2.48 per share

Tax withholding reference price $2.48 per share Price used for 14,756-share tax-withholding disposition

Post-transaction holdings 449,807 shares Common stock directly owned after April 15, 2026 transactions

Shares from RSU exercise 37,500 shares Common stock received upon RSU conversion

Initial RSU grant date October 15, 2024 Grant date for the reported RSU award

Remaining RSU vesting date October 15, 2026 Scheduled vesting date for remaining RSUs

Key Terms

Restricted Stock Units (RSUs), contingent right, tax withholding obligations, vesting, +1 more

5 terms

Restricted Stock Units (RSUs) financial

"security_title": "Restricted Stock Units (RSUs)""

Restricted stock units (RSUs) are a type of company promise to give employees shares of stock in the future, usually after certain conditions like working for a set time. They are like a gift promised today that you receive later, which can become valuable if the company's stock price goes up. RSUs matter because they are a way companies reward employees and can be a significant part of compensation.

contingent right financial

"Each RSU represents a contingent right to receive one share"

tax withholding obligations financial

"withheld by the Registrant to satisfy tax withholding obligations"

vesting financial

"in connection with the vesting."

Vesting is the process by which you earn full ownership of something, like company stock or a retirement benefit, over time. It’s like earning the right to keep a gift piece by piece the longer you stay with a company, making sure employees stay committed before they receive all the benefits.

Exercise or conversion of derivative security financial

"transaction_code_description": "Exercise or conversion of derivative security""

Form 4 Insider Transactions: What Each Field Means →

04/17/2026 - 08:39 AM

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^*

Marmurek Eric S

(Last)

(First)

(Middle)

6500 CHASE OAKS BLVD.

STE. 100

(Street)

PLANO

TEXAS

75023

(City)

(State)

(Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
Ribbon Communications Inc. [ RBBN ]

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

	Director	10% Owner
X	Officer (give title below)	Other (specify below)
	SVP, Deputy CFO and CAO

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
04/15/2026

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)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	04/15/2026		M		37,500	A	⁽¹⁾	464,563	D
Common Stock	04/15/2026		F		14,756	D	$2.48⁽²⁾	449,807	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)
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)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
Restricted Stock Units (RSUs)	⁽¹⁾	04/15/2026		M			37,500	⁽³⁾	⁽³⁾	Common Stock	37,500	$0	37,500	D

Explanation of Responses:

1. Eash RSU represents a contingent right to receive one share of the Registrant's common stock.

2. Reflects shares of common stock withheld by the Registrant to satisfy tax withholding obligations in connection with the vesting.

3. The RSUs were issued on October 15, 2024. The remaining RSUs vest on October 15, 2026.

	Patrick Macken, By POA from Rick Marmurek	04/17/2026
	** 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)

Source: View Original Filing on SEC EDGAR

FAQ

What insider activity did RBBN SVP Eric Marmurek report on this Form 4?

Eric S. Marmurek exercised 37,500 Restricted Stock Units into 37,500 shares of Ribbon Communications common stock. The transaction reflects a routine equity compensation vesting rather than an open-market purchase or sale by the executive.

How many RBBN shares were withheld for taxes in this Form 4 filing?

The company withheld 14,756 shares of Ribbon common stock at $2.48 per share to cover tax obligations. This tax-withholding disposition is not an open-market sale and occurs automatically when RSUs vest and trigger taxable income.

How many Ribbon Communications (RBBN) shares does Eric Marmurek now hold?

Following the RSU exercise and tax withholding, Eric S. Marmurek directly holds 449,807 shares of Ribbon Communications common stock. This post-transaction balance includes the newly vested shares net of the portion withheld to satisfy associated tax liabilities.

Were the RBBN transactions on this Form 4 open-market buys or sells?

No, the reported transactions were not open-market buys or sells. They represent the exercise of 37,500 Restricted Stock Units and a related tax-withholding disposition of 14,756 shares, both tied to equity compensation vesting rather than discretionary trading in the market.

When were the RSUs in this RBBN Form 4 originally granted and when do the remaining units vest?

The Restricted Stock Units were issued on October 15, 2024. Footnotes state that the remaining RSUs from this grant are scheduled to vest on October 15, 2026, indicating a multi-year vesting schedule for this equity award.