Gulf Coast Ultra Deep Royalty Trust

The Royalty Trust units have been quoted on the OTCID Basic Market (OTCID), operated by OTC Markets Group Inc., since July 1, 2025, having previously been quoted on the OTC Pink Market (OTC Pink), in each case under the symbol “GULTU.” For information regarding the OTCID and fluctuations in the market price and trading volume of the Royalty Trust units, see Part I, Item 1A. “Risk Factors – There is a limited public market for the Royalty Trust units, which could affect the market price, trading volume, liquidity and resale price of the Royalty Trust units” of this Form 10-K.

The following table shows the high and low sales/bid prices, as applicable, per Royalty Trust unit as reported on the OTC Pink for 2024 and the first two quarters of 2025, and as reported on the OTCID for the final two quarters of 2025. Quotations on the OTC Pink and the OTCID reflect bid and ask quotations, may reflect inter-dealer prices, without retail markup, markdown or commission, and may not represent actual transactions.

As of March 20, 2026, the 230,172,696 Royalty Trust units outstanding were held by 3,873 Royalty Trust unitholders of record.

Recent Sales of Unregistered Securities and Royalty Trust Unitholder Matters

There were no equity securities sold by the Royalty Trust during the year ended December 31, 2025. At December 31, 2025, the Royalty Trust had 230,172,696 Royalty Trust units outstanding.

Purchases of Royalty Trust Units by the Issuer and Affiliated Purchasers

None.