X0306 4 2021-11-30 false 0001626450 BigCommerce Holdings, Inc. BIGC 0001513984 Bellm Brent 11305 FOUR POINTS DRIVE BUILDING II, THIRD FLOOR AUSTIN TX 78726 true true false false President Chief Exec Officer Series 1 Common Stock 2021-08-12 5 G false E 237588.00 0.00 D 422319.00 I By Brent Bellm through his partnership interests in Elkmont Ltd. Series 1 Common Stock 2021-08-12 5 G false E 240227.00 0.00 D 419680.00 I By Hilary Bellm through her partnership interests in Elkmont Ltd. Series 1 Common Stock 2021-11-30 4 P false 422319.00 A 659907.00 I By Hilary Bellm 2021 Family Trust through its partnership interest in Elkmont Ltd. Series 1 Common Stock 2021-11-30 4 P false 419680.00 A 659907.00 I By Brent Bellm Spousal Trust through its partnership interest in Elkmont Ltd. Series 1 Common Stock 2021-11-30 4 S false 422319.00 D 0.00 I By Brent Bellm through his partnership interests in Elkmont Ltd. Series 1 Common Stock 2021-11-30 4 S false 419680.00 D 0.00 I By Hilary Bellm through her partnership interests in Elkmont Ltd. Series 1 Common Stock 100389.00 I By Mt. Eden Ltd. Series 1 Common Stock 496696.00 I By Wild Basin, Ltd. Series 1 Common Stock 0.00 I By Hilary Bellm Series 1 Common Stock 349356.00 D In connection with the reporting person's estate plan, the reporting person and the reporting person's spouse each transferred 659,907 shares to Elkmont Ltd. ("Elkmont"), a limited partnership of which the reporting person and the reporting person's spouse are the sole limited partners. The reporting person is the sole manager of Elkmont Investment Management, LLC, a limited liability company that is the sole general partner of Elkmont and wholly owned by the reporting person and the reporting person's spouse. In connection with the reporting person's estate plan, the reporting person and the reporting person's spouse gifted 18.0% and 18.2%, respectively, of the limited partnership interests in Elkmont to intentionally defective grantor trusts ("IDGT"), the sole beneficiaries of which are the reporting person or the reporting person's spouse and the reporting person's children. The reporting person is the sole trustee of the IDGTs. This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted on August 18, 2021. In connection with the reporting person's estate plan and following the aforementioned transactions, the reporting person and the reporting person's spouse sold 31.9984% and 31.7984%, respectively, limited partnership interests in Elkmont to the IDGTs in a private transaction. The Elkmont limited partnership interests were sold to the IDGTs in exchange for the issuance of promissory notes in favor of the reporting person and the reporting person's spouse, in an aggregate amount equal to the fair market value of the partnership interests on November 30, 2021, as determined by an independent appraiser within 90 days of the transaction. /s /Jeff Mengoli, Attorney-in-Fact for Brent Bellm 2021-12-02