Marmurek Eric S 4

What Happened
Eric S. Marmurek, Chief Financial Officer of Ribbon Communications (RBBN), had a series of restricted share units (RSUs) and performance share units (PSUs) convert into common stock on April 17, 2026 and May 15, 2026. A total of 154,814 shares were issued upon vesting/conversion (codes M — exercise/conversion of derivative). To satisfy tax withholding obligations (code F), the issuer withheld 61,005 shares for taxes, generating cash of approximately $162,779. Net shares added to Marmurek’s position after withholding were about 93,809 shares.

Key Details

• Transaction dates: April 17, 2026 and May 15, 2026; Form 4 filed May 19, 2026.
• Shares issued on vesting/conversion (M): 154,814 total (48,328; 25,651 on 4/17; 23,146; 31,646; 26,043 on 5/15).
• Shares withheld for taxes (F): 61,005 shares (19,107 and 10,092 on 4/17 at $2.71; 9,107, 12,452, 10,247 on 5/15 at $2.63) totaling ~$162,779.
• Net new shares to Marmurek after withholding: ~93,809 shares.
• Footnotes: RSUs/PSUs convert one-for-one (F1). PSU payout percentages for the related performance periods are disclosed (see F3–F5) and certain RSU vesting schedules noted (F6–F7). F2 confirms shares were withheld to satisfy tax withholding.
• Filing timeliness: Form filed May 19, 2026. The April 17, 2026 vesting appears to have been reported after the SEC’s usual two-business-day Form 4 deadline (i.e., late); the May 15, 2026 items were reported on May 19 (within two business days).

Context

• These were not open-market purchases or discretionary sales but automatic conversions of RSUs/PSUs into common stock (derivative exercises/vesting). The withheld shares reflect standard tax withholding by the company rather than a market sale by the insider.
• PSUs include performance-based awards; footnotes show percent-of-target earned for each award period, including a relative TSR-based PSU that paid at 130% of target for its period.
• For retail investors: such vesting is routine compensation realization by executives and does not necessarily signal a view on the stock. The main takeaways are the scale of the award and the number of shares withheld for taxes.