Exhibit 4.1

ARC GROUP SECURITIES ACQUISITION I

UNITS CONSISTING OF ONE CLASS A ORDINARY SHARE AND ONE REDEEMABLE WARRANT AND ONE RIGHT THAT ENTITLES THE HOLDER THEREOF TO RECEIVE ONE-QUARTER OF ONE CLASS A ORDINARY SHARE

THIS CERTIFIES THAT ________________________ is the owner of ______________________ Units of ARC Group Securities Acquisition I, a Cayman Islands exempted company (the “Company”), transferrable on the books of the Company in person or by duly authorized attorney upon surrender of this certificate properly endorsed.

Each Unit (“Unit”) consists of one (1) Class A ordinary share, par value $0.0001 per share (“Ordinary Share”), of the Company, and one redeemable warrant (“Warrant”) and one right that entitles the holder thereof to receive one-quarter (1/4) of one Ordinary Share (“Right”). Each Warrant entitles the holder to purchase one Ordinary Share (subject to adjustment) for $11.50 per share (subject to adjustment). Each Warrant will become exercisable thirty (30) days after the Company’s completion of a merger, amalgamation, share exchange, asset acquisition, share purchase, reorganization or other similar business combination involving the Company, with one or more businesses or assets (each a “Business Combination”), and will expire unless exercised before 5:00 p.m., New York City Time, on the date that is five (5) years after the date on which the Company completes its initial Business Combination, or earlier upon redemption or liquidation (the “Expiration Date”). The Ordinary Shares, Warrants and Rights comprising the Units represented by this certificate are not transferable separately prior to the 52nd day following the date of the registration statement, unless ARC Group Securities LLC elects to allow separate trading earlier, subject to the Company’s filing of a Current Report on Form 8-K with the Securities and Exchange Commission containing an audited balance sheet reflecting the Company’s receipt of the gross proceeds of the Company’s initial public offering and issuing a press release announcing when separate trading will begin. No fractional Warrants or Rights will be issued upon separation of the Units. The terms of the Warrants are governed by a Warrant Agreement, dated as of [_], 2026 (the “Warrant Agreement”), between the Company and Efficiency INC., as Warrant Agent, and are subject to the terms and provisions contained therein, all of which terms and provisions the holder of this certificate consents to by acceptance hereof. The terms of the Rights are governed by a Rights Agreement, dated as of [_], 2026 (the “Rights Agreement”), between the Company and [Efficiency INC.], as Rights Agent, and are subject to the terms and provisions contained therein, all of which terms and provisions the holder of this certificate consents to by acceptance hereof. Copies of the Warrant Agreement and Rights Agreement are on file at the office of the Warrant and Rights Agent at 2440 Sand Hill Rd., Unit 101, Menlo Park, CA 94025, and are available to any Warrant or Rights holder on written request and without cost.

This certificate is not valid unless countersigned by the Transfer Agent and registered by the Registrar of the Company.

This certificate shall be governed by and construed in accordance with the internal laws of the State of New York.

Witness the facsimile signature of a duly authorized signatory of the Company.

ARC Group Securities Acquisition I

The Company will furnish without charge to each unitholder who so requests, a statement of the powers, designations, preferences and relative, participating, optional or other special rights of each class of shares or series thereof of the Company and the qualifications, limitations, or restrictions of such preferences and/or rights.

The following abbreviations, when used in the inscription on the face of this certificate, shall be construed as though they were written out in full according to applicable laws or regulations:

Additional abbreviations may also be used though not in the above list.

For value received, hereby sell, assign and transfer unto

(PLEASE INSERT SOCIAL SECURITY OR OTHER IDENTIFYING NUMBER OF ASSIGNEE)

(PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS, INCLUDING ZIP CODE, OF ASSIGNEE)

Units represented by the within certificate, and do hereby irrevocably constitute and appoint

Attorney to transfer the said Units on the books of the within named Company with full power of substitution in the premises.

Signature(s) Guaranteed:

In each case, as more fully described in, and subject to the terms and conditions described in, the Company’s final prospectus for its initial public offering dated [●] 2026, the holder(s) of this certificate shall have the opportunity to receive a pro-rata portion of certain funds held in the trust account established in connection with the Company’s initial public offering regardless of whether they abstain, vote for, or vote against, the Company’s initial Business Combination only in the event that (i) the Company redeems the Ordinary Shares issued as part of the Units sold in the Company’s initial public offering (the “Public Shares”) and liquidates because it does not consummate an initial Business Combination within the time period set forth in the Company’s amended and restated memorandum and articles of association, as amended and restated from time to time (the “Articles”), or such later time as the shareholders of the Company may approve in accordance with the Articles (the “Completion Window”), (ii) the Company redeems the Public Shares in connection with a shareholder vote to amend the Articles (A) to modify the substance or timing of the Company’s obligation to allow redemptions in connection with the Company’s initial Business Combination or the Company’s obligation to redeem one hundred per cent (100%) of the Public Shares if the Company has not consummated an initial Business Combination within the Completion Window, or (B) with respect to any other material provisions of the Articles relating to the shareholders’ rights or pre-initial Business Combination activity, or (iii) if the holder(s) properly redeem(s) for cash his, her or its or their respective Ordinary Shares issued as part of the Units represented by this certificate in connection with a tender offer (or proxy solicitation, solely in the event the Company seeks shareholder approval of the proposed initial Business Combination) setting forth the details of a proposed initial Business Combination. In no other circumstances shall the holder(s) have any right or interest of any kind in or to the trust account.