Grayscale Sui Staking ETF

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

For the fiscal year ended December 31,2025

or

For the transition period from _____ to ______

Commission File Number 001-43131

Grayscale Sui Staking ETF

SPONSORED BY GRAYSCALE INVESTMENTS SPONSORS, LLC

(Exact Name of Registrant as Specified in Its Charter)

(212)668-1427

(Registrant’s telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes ☐No ☒

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes ☐No ☒

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☐No ☒

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes ☒ No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☒

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report.☐

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements.☐

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b). ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ☐ No☒

Aggregate market value of registrant’s Shares held by non-affiliates of the registrant, based upon the closing price of a Share on June 30, 2025, as reported by NYSE Arca, Inc. on that date: Not applicable

Number of Shares of the registrant outstanding as of March 19, 2026:1,718,900

DOCUMENTS INCORPORATED BY REFERENCE: None

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Industry and Market Data

Although we are responsible for all disclosure contained in this Annual Report on Form 10-K, in some cases we have relied on certain market and industry data obtained from third-party sources that we believe to be reliable. Market estimates are calculated by using independent industry publications in conjunction with our assumptions regarding the Sui industry and market. While we are not aware of any misstatements regarding any market, industry or similar data presented herein, such data involves risks and uncertainties and is subject to change based on various factors, including those discussed under the headings “Forward-Looking Statements” and “Item 1A. Risk Factors” in this Annual Report.

Forward-Looking Statements

This Annual Report on Form 10-K contains “forward-looking statements” with respect to the financial conditions, results of operations, plans, objectives, future performance and business of Grayscale Sui Staking ETF (the “Trust”). Statements preceded by, followed by or that include words such as “may,” “might,” “will,” “should,” “expect,” “plan,” “anticipate,” “believe,” “estimate,” “predict,” “potential” or “continue,” the negative of these terms and other similar expressions are intended to identify some of the forward-looking statements. All statements (other than statements of historical fact) included in this Annual Report that address activities, events or developments that will or may occur in the future, including such matters as changes in market prices and conditions, the Trust’s operations, the plans of Grayscale Investments Sponsors, LLC (the “Sponsor”), and references to the Trust’s future success and other similar matters are forward-looking statements. These statements are only predictions. Actual events or results may differ materially from such statements. These statements are based upon certain assumptions and analyses the Sponsor made based on its perception of historical trends, current conditions and expected future developments, as well as other factors appropriate in the circumstances. Whether or not actual results and developments will conform to the Sponsor’s expectations and predictions, however, is subject to a number of risks and uncertainties, including, but not limited to, those described in “Part I, Item 1A. Risk Factors.” Forward-looking statements are made based on the Sponsor’s beliefs, estimates and opinions on the date the statements are made and neither the Trust nor the Sponsor is under a duty or undertakes an obligation to update forward-looking statements if these beliefs, estimates and opinions or other circumstances should change, other than as required by applicable laws. Investors are therefore cautioned against relying on forward-looking statements. Factors which could have a material adverse effect on the Trust’s business, financial condition or results of operations and future prospects or which could cause actual results to differ materially from the Trust’s expectations include, but are not limited to, those described in “Item 1A. Risk Factors.”

Summary of Risk Factors

Below is a summary of the principal factors that make an investment in the Shares speculative or risky. This summary does not address all of the risks that we face. Additional discussion of the risks summarized in this risk factor summary, and other risks that we face, can be found below in “Item 1A. Risk Factors.” Some of the factors that could materially and adversely affect our business include, but are not limited to, the following:

Risk Factors Related to Digital Assets

•

Extreme volatility of trading prices that many digital assets, including SUI, have experienced in recent periods and may continue to experience, could have a material adverse effect on the value of the Shares and the Shares could lose all or substantially all of their value.

•

The medium-to-long term value of the Shares is subject to a number of factors relating to the capabilities and development of blockchain technologies and to the fundamental investment characteristics of digital assets.

•

Digital assets represent a relatively new and rapidly evolving industry, and the value of the Shares depends on the acceptance of SUI.

•

Digital assets may have concentrated ownership and large sales or distributions by holders of such digital assets could have an adverse effect on the market price of such digital assets.

•

A temporary or permanent “fork” or a “clone” could adversely affect the value of the Shares.

Risk Factors Related to the Digital Asset Markets

•

Recent developments in the digital asset economy have led to extreme volatility and disruption in digital asset markets, a loss of confidence in participants of the digital asset ecosystem, significant negative publicity surrounding digital assets broadly and market-wide declines in liquidity.

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•

The value of the Shares relates directly to the value of SUI held by the Trust, the value of which may be highly volatile and subject to fluctuations.

•

The largely unregulated nature and lack of transparency surrounding the operations of Digital Asset Trading Platforms may adversely affect the value of digital assets and, consequently, the value of the Shares.

•

Digital Asset Trading Platforms may be exposed to front-running and wash-trading.

•

The Index has a limited history and a failure of the Index Price could adversely affect the value of the Shares.

•

Competition from the emergence or growth of other digital assets could have a negative impact on the price of SUI and adversely affect the value of the Shares.

Risk Factors Related to the Trust and the Shares

•

The Trust relies on third-party service providers to perform certain functions essential to the affairs of the Trust and the replacement of such service providers could pose challenges to the safekeeping of the Trust’s SUI and to the operations of the Trust.

•

The liquidity of the Shares may be affected if Authorized Participants cease to perform their obligations under the Participant Agreements or the Liquidity Engager is unable to engage Liquidity Providers.

•

The Shares may trade at a price that is at, above or below the Trust’s NAV per Share as a result of the non-concurrent trading hours between NYSE Arca and the Digital Asset Trading Platform Market.

•

Any suspension or other unavailability of the Trust’s redemption program may cause the Shares to trade at a discount to the NAV per Share.

•

Shareholders may suffer a loss on their investment if the Shares trade above or below the Trust’s NAV per Share.

•

The limited ability to facilitate in-kind creations and redemptions of Shares could have adverse consequences for the Trust.

•

Extraordinary expenses, tax liabilities arising from SUI sales without distributions, indemnification obligations, intellectual property claims, and disruptions from pandemics or other disasters could adversely affect the value of the Shares.

Risk Factors Related to the Regulation of Digital Assets, the Trust and the Shares

•

A determination that SUI or any other digital asset is or involves a transaction in a “security” may adversely affect the value of SUI and the value of the Shares, and result in potentially extraordinary, nonrecurring expenses to, or termination of, the Trust.

•

Regulatory changes or actions by the U.S. Congress or any U.S. federal or state agencies may affect the value of the Shares or restrict the use of one or more digital assets, validating activity or the operation of their networks or the Digital Asset Markets in a manner that adversely affects the value of the Shares.

•

Regulatory changes or other events in foreign jurisdictions may affect the value of the Shares or restrict the use of one or more digital assets, validating activity or the operation of their networks or the Digital Asset Trading Platform Market in a manner that adversely affects the value of the Shares.

•

The Authorized Participant, the Trust or the Sponsor could be subject to regulation as a money service business or money transmitter, which could result in extraordinary expenses to the Authorized Participant, the Trust or the Sponsor and also result in decreased liquidity for the Shares.

•

Regulatory changes or interpretations could obligate the Trust or the Sponsor to register and comply with new regulations, resulting in potentially extraordinary, nonrecurring expenses to the Trust.

•

The uncertain and evolving tax treatment of the Trust, digital assets, SUI and transactions involving SUI under U.S. federal, state, and local tax laws could adversely affect the value of the Shares.

Risk Factors Related to Potential Conflicts of Interest

•

Conflicts of interest may arise among the Sponsor or its affiliates and the Trust.

•

Shareholders cannot be assured of the Sponsor’s continued services, the discontinuance of which may be detrimental to the Trust.

•

If the Custodian resigns or is removed by the Sponsor, or otherwise, without replacement, it would trigger early termination of the Trust.

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Risk Factors Related to Staking

•

The lack of ability to participate in any different form of Staking to the extent the Staking Condition is not satisfied, which could have adverse consequences for the Trust.

•

Staking introduces a risk of loss of SUI which could adversely affect the value of the Shares.

•

Staked SUI tokens will be inaccessible for a variable period of time, determined by a range of factors, which could result in certain liquidity risk to the Trust.

•

The Trust will be dependent on third parties to effectively execute the Trust’s Staking Arrangements.

•

The regulatory landscape surrounding Staking is uncertain.

•

Beneficial owners of Shares could incur tax liabilities without receiving corresponding distributions from the Trust.

Unless otherwise stated or the context otherwise requires, the terms “we,” “our” and “us” in this Annual Report refer to the Sponsor acting on behalf of the Trust.

A glossary of industry and other defined terms is included in this Annual Report, beginning on page 107.

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Table of Contents

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PART