Material Event Form 8 K

Item 8.01. Other Events.

On July 24, 2024, Allegro MicroSystems, Inc. (the "Company") entered into an underwriting agreement (the "Underwriting Agreement") with Barclays Capital Inc. and Morgan Stanley & Co. LLC, as representatives (the "Representatives") of the several underwriters (the "Underwriters") listed in Schedule I of the Underwriting Agreement, pursuant to which the Company agreed to sell 25,000,000 shares (the "Firm Shares") of the Company's common stock, par value $0.01 per share, to the Underwriters at a price of $23.16 per share ("Common Stock"). Under the terms of the Underwriting Agreement, the Company granted the Underwriters a 30-day option to purchase up to an additional 3,750,000 shares of Common Stock (together with the Firm Shares, the "Shares") at the same purchase price, which option was exercised in full prior to the closing of the offering. The offering for the entire amount of the Shares closed on July 26, 2024.

The offering was made pursuant to an effective Shelf Registration Statement on Form S-3 (File No. 333-280960) (the "Registration Statement") and a related prospectus supplement filed with the Securities and Exchange Commission.

The Underwriting Agreement contains customary representations, warranties and covenants and includes the terms and conditions for the sale of the Shares by the Company to the Underwriters, indemnification and contribution obligations and other terms and conditions customary in agreements of this type.

A copy of the Underwriting Agreement is filed as Exhibit 1.1 to this Current Report on Form 8-K and is incorporated herein and in the Registration Statement by reference. The above description is qualified in its entirety by reference to such exhibit.

Davis Polk & Wardwell LLP, counsel to the Company, has issued an opinion to the Company, dated July 26, 2024, regarding the validity of the Shares. A copy of the opinion is filed as Exhibit 5.1 to this Current Report on Form 8-K and is incorporated in the Registration Statement by reference.