Andersen Group Inc.

S-11 d132575ds1.htm S-1

As filed with the Securities and Exchange Commission on August 17, 2026.

Registration Statement No. 333-

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORMS-1

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933*** ***** **

(Exact name of Registrant as specified in its charter)

333 Bush Street

Suite 1700

San Francisco, California 94104

(415)764-2700

(Address, including zip code, and telephone number, including area code, of Registrant’s principal executive offices)

Mark L. Vorsatz

Chairman and Chief Executive Officer

333 Bush Street

Suite 1700

San Francisco, California 94104

(415)764-2700

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

**Approximate date of commencement of proposed sale to the public:**As soon as practicable after the effective date of this registration statement.

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, as amended, check the following box.☐

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.☐

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.☐

If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration number of the earlier effective registration statement for the same offering.☐

Indicate by check mark whether the Registrant is a large accelerated filer, an accelerated filer, anon-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 7(a)(2)(B) of the Securities Act of 1933, as amended.☐

The Registrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment that specifically states that this Registration Statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933, as amended, or until the Registration Statement shall become effective on such date as the Securities and Exchange Commission, acting pursuant to said Section 8(a), may determine.

The information in this preliminary prospectus is not complete and may be changed. The selling stockholders may not sell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This preliminary prospectus is not an offer to sell these securities and it is not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

PRELIMINARY PROSPECTUS (Subject to Completion)

Issued August 17, 2026

**4,284,457 Shares

Class A Common Stock

The selling stockholders named in this prospectus are offering 4,284,457 shares of our Class A common stock. Our shares of Class A common stock are listed on the New York Stock Exchange (the NYSE) under the symbol “ANDG.” On August 14, 2026, the closing sales price of our shares of Class A common stock as reported on the NYSE was $48.89 per share. We will not receive any proceeds from the sale of shares of our Class A common stock by the selling stockholders.

Immediately prior to this offering, the selling stockholders redeemed Class X Aggregator Units (as defined herein) for an equal number of (i) Class X Umbrella Units (as defined herein) and (ii) shares of our Class B common stock then held by Aggregator (as defined herein), and subsequently redeemed such Class X Umbrella Units (with the cancellation of the paired shares of Class B common stock) for the shares of our Class A common stock to be sold in this offering. See the sections titled “Principal and Selling Stockholders” and “Organizational Structure.”

We have two series of authorized common stock, Class A common stock and Class B common stock. Each share of our Class A common stock is entitled to one vote per share. Each share ofour non-economic Class B common stock is entitled to ten votes per share. Aggregator holds all outstanding shares of our Class B common stock. Immediately after this offering, Aggregator will own approximately 98.1% of the combined voting power of our outstanding capital stock. As a result, we are, and will remain after this offering, a “controlled company” within the meaning of the corporate governance standards of the NYSE.

Investing in our Class A common stock involves risks. See the section titled “Risk Factors” beginning on page 23.

The selling stockholders have granted the underwriters an option to purchase up to an additional 642,668 shares of our Class A common stock at the public offering price less the underwriting discounts and commissions within 30 days from the date of this prospectus.

The underwriters expect to deliver the shares of our Class A common stock to purchasers on or about , 2026.

The Securities and Exchange Commission and state securities regulators have not approved or disapproved these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

, 2026