SCHEDULE 13D/A 0001193125-22-042323 0001508902 XXXXXXXX LIVE 5 Common Stock 11/08/2024 false 0001819994 773122106 Rocket Lab USA, Inc.

3881 McGowen Street Long Beach CA 90808

Bessemer Venture Partners (914) 833-5300 1865 Palmer Avenue Suite 104 Larchmont NY 10528 0001508902 N Bessemer Venture Partners VIII Institutional L.P. b WC N E9 4460065 0 4460065 0 4460065 N 0.9 PN 0001508900 N Bessemer Venture Partners VIII L.P. b WC N E9 3708551 0 3708551 0 3708551 N 0.7 PN 0001559306 N Deer VIII & Co. L.P. b AF N E9 8168616 0 8168616 0 8168616 N 1.6 PN 0001559311 N Deer VIII & Co. Ltd. b AF N E9 8168616 0 8168616 0 8168616 N 1.6 CO Common Stock Rocket Lab USA, Inc. 3881 McGowen Street Long Beach CA 90808 This Amendment No. 5 (this "Amendment") to Schedule 13D (the "Schedule 13D") is being filed by Bessemer Venture Partners VIII Institutional L.P. ("BVP VIII Inst"), Bessemer Venture Partners VIII L.P. ("BVP VIII", and together with BVP VIII Inst, the "BVP VIII Funds"), Deer VIII & Co. L.P. ("Deer VIII LP"), and Deer VIII & Co. Ltd., ("Deer VIII Co," and collectively with the BVP VIII Funds and Deer VIII LP, the "Reporting Persons"), which is the general partner of Deer VIII LP. Capitalized terms used but not otherwise defined in this Amendment shall have the meanings ascribed to them in the Schedule 13D. Except as otherwise specifically amended in this Amendment, items in the Schedule 13D remain unchanged. As of December 31, 2024, BVP VIII Inst had sole voting and dispositive power with respect to 4,460,065 shares of Common Stock of the Issuer, constituting approximately 0.9% of the Issuer's Common Stock. As of December 31, 2024, BVP VIII had sole voting and dispositive power with respect to 3,708,551 shares of Common Stock of the Issuer, constituting approximately 0.7% of the Issuer's Common Stock. As of December 31, 2024, Deer VIII LP, as the general partner of each of the BVP VIII Funds may be deemed to have sole voting and dispositive power with respect to all 8,168,616 shares of Common Stock of the Issuer owned by the BVP VIII Funds, constituting approximately 1.6% of the Issuer's Common Stock. As of December 31, 2024, Deer VIII Co, as the general partner of Deer VIII LP may be deemed to have sole voting and dispositive power with respect to all 8,168,616 shares of Common Stock of the Issuer owned by the BVP VIII Funds, constituting approximately 1.6 % of the Issuer's Common Stock. The percent of class was calculated based on 499,911,078 shares of Common Stockissued and outstanding as of November 7, 2024as disclosed in the Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission by Rocket Lab USA, Inc. on November 12, 2024. The shares of Issuer's Common Stock reported in this Item 5 do not include the Earnout Shares described in Item 4 of the Schedule 13D. Regarding the number of shares as to which such person has: (i) sole power to vote or to direct the vote: See line 7 of cover sheets (ii) shared power to vote or to direct the vote: See line 8 of cover sheets (iii) sole power to dispose or to direct the disposition: See line 9 of cover sheets. (iv) shared power to dispose or to direct the disposition: See line 10 of cover sheets No Reporting Person has effected any transaction in the Issuer's Common Stock during the past 60 days. No other person is known to have the right to receive or the power to direct the receipt of dividends from, or any proceeds from the sale of, shares of the Issuer's Common Stock beneficially owned by any of the Reporting Persons. On November 8, 2024 each of the Reporting Persons ceased to be the beneficial owner of more than five percent of the shares of Common Stock. Bessemer Venture Partners VIII Institutional L.P. /s/ Scott Ring 02/14/2025 Bessemer Venture Partners VIII L.P. /s/ Scott Ring 02/14/2025 Deer VIII & Co. L.P. /s/ Scott Ring 02/14/2025 Deer VIII & Co. Ltd. /s/ Scott Ring 02/14/2025