Bain Capital GSS Investment Corp.

We have neither engaged in any operations nor generated any operating revenues to date. Our only activities from March 24, 2025 (inception) through September 30, 2025 were organizational activities and identifying a target company for a business combination. We do not expect to generate any operating revenues until after the completion of our initial business combination. We will generatenon-operating income in the form of interest and dividend income on cash and investments held after the Initial Public Offering. We incur expenses as a result of being a public company (for legal, financial reporting, accounting and auditing compliance), as well as for due diligence expenses.

For the three months ended September 30, 2025 and for the period from March 24, 2025 (inception) through September 30, 2025, we had a net loss of $20,600 and $71,168, respectively, which consists of general and administrative costs.

Liquidity and Capital Resources

Until the consummation of the initial public offering, our only source of liquidity was an initial purchase of shares of Class B ordinary shares, par value $0.0001 per share (the “Founder Shares”), by the Sponsor, and loans from the Sponsor, which were repaid at the closing of the initial public offering. As of September 30, 2025, we had $2,000,000 in cash and working capital deficit of $7,654,068.

Subsequent to the period covered by this Quarterly Report, on October 1, 2025, we consummated the Initial Public Offering of 46,000,000 Units, which includes the full exercise by the underwriters of their over-allotment option in the amount of 6,000,000 Units, at $10.00 per Unit, generating gross proceeds of $460,000,000. Simultaneously with the closing of the Initial Public Offering, we consummated the sale of 900,000 Private Placement Units, at a price of $10.00 per Private Placement Unit, in a private placement to the Sponsor, generating gross proceeds of $9,000,000.

Following the closing of the initial public offering and the private placement, a total of $460,000,000 was placed in the Trust Account. The proceeds held in the trust account will be invested only in U.S. government treasury obligations with a maturity of 185 days or less or in money market funds meeting certain conditions under Rule 2a-7 under the Investment Company Act which invest only in direct U.S. government treasury obligations and/or held as cash or cash items (including in demand deposit accounts). We may withdraw interest from the Trust Account to pay taxes, if any. We intend to use substantially all of the funds held in the Trust Account, including any amounts representing interest earned on the Trust Account (less income taxes payable), to complete our Business Combination. To the extent that our share capital or debt is used, in whole or in part, as consideration to complete our Business Combination, the remaining proceeds held in the Trust Account will be used as working capital to finance the operations of the target business or businesses, make other acquisitions and pursue our growth strategies. We incurred transaction costs amounting to $23,835,700, consisting of $7,000,000 of cash underwriting fee (net of $1,000,000 underwriters’ reimbursement), $16,100,000 of deferred underwriting fee, and $735,700 of other offering costs.

The remaining proceeds from the Initial Public Offering and the Private Placement are held outside the trust account, in the cash operating account amounting to $1,227,213 as of October 1, 2025. Such funds are being used primarily to enable us to identify a target and to negotiate and consummate our initial Business Combination.

As of September 30, 2025, we had cash of $2,000,000. We intend to use the funds held outside the Trust Account primarily to identify and evaluate target businesses, perform business due diligence on prospective target businesses, travel to and from the offices, plants or similar locations of prospective target businesses or their representatives or owners, review corporate documents and material agreements of prospective target businesses, and structure, negotiate and complete a Business Combination.

In order to fund working capital deficiencies or finance transaction costs in connection with an intended initial business combination, our Sponsor or an affiliate of our Sponsor or certain of our officers and directors may, but are not obligated to, loan us funds as may be required. If we complete our initial Business Combination, we may repay such loaned amounts. In the event that our initial business combination does not close, we may use a portion of the working capital held outside the Trust Account to repay such loaned amounts but no proceeds from our Trust Account would be used for such repayment. Up to $1,500,000 of such loans may be convertible into units of the post-business combination company at a price of $10.00 per unit at the option of the lender. The units would be identical to the Private Placement Units. The terms of such loans, if any, have not been determined and no written agreements exist with respect to such loans. Prior to the completion of our initial Business Combination, we do not expect to seek loans from parties other than our Sponsor, members of our management team or any of their affiliates as we do not believe third parties will be willing to loan such funds and provide a waiver against any and all rights to seek access to funds in our Trust Account.

We do not believe we will need to raise additional funds in order to meet the expenditures required for operating our business. However, if our estimate of the costs of identifying a target business, undertakingin-depth due diligence and negotiating a business combination are less than the actual amount necessary to do so, we may have insufficient funds available to operate our business prior to our business combination. Moreover, we may need to obtain additional financing either to complete our business combination or because we become obligated to redeem a significant number of our public shares upon consummation of our business combination, in which case we may issue additional securities or incur debt in connection with such business combination.

Off-Balance Sheet Arrangements

We did not have anyoff-balance sheet arrangements as of September 30, 2025.

Contractual Obligations

We do not have any long-term debt, capital lease obligations, operating lease obligations or long-term liabilities, other than an agreement to pay the Sponsor $20,000 per month for office space, secretarial and administrative services.

The underwriters were paid a cash underwriting discount of $0.20 per Unit, or $8,000,000 in the aggregate, upon the closing of the Initial Public Offering excluding the units issued pursuant to the full exercise of the over-allotment option. The underwriters paid the Company an aggregate amount of $1,000,000 at the closing of the Initial Public Offering as reimbursement to the Company for certain of its expenses and fees incurred in connection with the Initial Public Offering. In addition, $0.35 per unit, or $16,100,000 in the aggregate will be payable to the underwriters for deferred underwriting commissions. The deferred fee will become payable to the underwriters from the amounts held in the Trust Account solely in the event that we complete a Business Combination, subject to the terms of the underwriting agreement.

Critical Accounting Policies

The preparation of condensed financial statements and related disclosures in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements, and income and expenses during the periods reported. Making estimates requires management to exercise significant judgement. It is at least reasonably possible that the estimate of the effect of a condition, situation or set of circumstances that existed at the date of the financial statements, which management considered in formulating its estimate, could change in the near term due to one or more future confirming events. Accordingly, the actual results could materially differ from those estimates. As of September 30, 2025, we did not have any critical accounting estimates to be disclosed.