Brilliant Earth (BRLT) 10% Owner Mainsail GP III Acquires 16,014 Shares

What Happened
Mainsail GP III, LLC (a general partner of Mainsail entities and a reported 10% owner of Brilliant Earth, ticker BRLT) reported a deemed acquisition on 2026-08-24 of 16,014 shares and a related derivative interest covering 16,014 shares. The Form 4 shows price as N/A, but a footnote states the aggregate consideration for the transaction was $18,096. The Reporting Persons note that this deemed purchase could be matched against prior sales (Aug 10, 2026) for Section 16(b) purposes; they have fully disgorged the Section 16(b) deemed profit of $2,033 to the issuer.

Key Details

• Transaction date: 2026-08-24; Form 4 filed 2026-08-26.
• Reported entries: two "Other acquisition or disposition (J)" records for 16,014 shares (one entry also labeled as derivative). Price listed as N/A on the Form 4; footnote reports aggregate consideration $18,096.
• Holdings reported (aggregate across related Mainsail vehicles): 31,098,704 Class B shares (MP III) + 61,823 (MIP) + 687,544 (MCOI) = 31,848,071 Class B shares/LLC Units.
• Notable footnotes: F1 explains the transaction was a purchase of a limited partner interest in Mainsail Co‑Investors III, L.P. and may represent a change in pecuniary interest; F3 clarifies GP III is an institutional general partner and disclaims beneficial ownership except for pecuniary interests. The Reporting Persons disgorged $2,033 of Section 16(b) profit.
• Filing timeliness: Filed two days after the transaction date (appears timely).

Context

• The reported securities are LLC Units that come with Class B common stock and are exchangeable for Class A common stock on a one-for-one basis (per footnote F4); these particular LLC Units were acquired prior to the issuer’s IPO and do not expire.
• This filing reflects institutional/partner-level activity (a co‑investment and GP interest), not a personal executive trade. Such transfers of co‑investment interests can alter pecuniary exposure without indicating insider views on company operations.
• Code J denotes "other acquisition or disposition" — the derivative entry indicates a change in derivative/pecuniary interest rather than a standard open‑market purchase or option exercise.