As Filed Pursuant to Rule 424(b)(5)
Registration No. 333-284510
PROSPECTUS SUPPLEMENT
(To Prospectus Supplement Dated
November 4, 2025, as supplemented by Supplement No. 1 thereto dated March 23, 2026, and Prospectus Dated January 27, 2025)
CLASS A COMMON STOCK ANNEX
Up to $21,000,000,000
Class A Common Stock
We have entered into an Omnibus Sales Agreement with TD Securities (USA) LLC, The Benchmark Company, LLC, StoneX Financial Inc.,
A.G.P./Alliance Global Partners, Barclays Capital Inc., BTIG, LLC, Canaccord Genuity LLC, Cantor Fitzgerald & Co., Clear Street LLC, Compass Point Research & Trading, LLC, H.C. Wainwright & Co., LLC, Keefe,
Bruyette & Woods, Inc., Maxim Group LLC, Mizuho Securities USA LLC, Moelis & Company LLC, Morgan Stanley & Co. LLC, Santander US Capital Markets LLC, SG Americas Securities, LLC, and TCBI Securities, Inc., doing business
as Texas Capital Securities (collectively, the “Agents”), dated November 4, 2025, relating to the sale of shares of our class A common stock, par value $0.001 per share, and shares of several series of our preferred stock, par value
$0.001 per share, as amended by Amendment No. 1 to Omnibus Sales Agreement, dated February 19, 2026, and Amendment No. 2 to Omnibus Sales Agreement, dated March 9, 2026 (as so amended and supplemented, the “Sales
Agreement”). On March 23, 2026, we entered into an Additional Program Addendum to the Sales Agreement with the Agents relating to the sale of additional shares of our class A common stock offered hereby (the “Sales Agreement
Addendum”). In accordance with the terms of the Sales Agreement, as supplemented by the Sales Agreement Addendum, under this prospectus supplement annex relating to the sale of our class A common stock (the “Common Stock Annex”),
we may offer and sell shares of our class A common stock having an aggregate offering price of up to $21,000,000,000 from time to time through one or more of the Agents, acting as our sales agents. The shares of class A common stock offered
hereunder are among the securities described in the base prospectus supplement dated November 4, 2025, that we filed with the Securities and Exchange Commission (the “SEC”) on such date, as supplemented by the supplement to the base
prospectus supplement dated March 23, 2026 (as supplemented, the “base prospectus supplement”) and a prospectus dated January 27, 2025. This Common Stock Annex should be read in conjunction with that accompanying base
prospectus supplement and prospectus and the contents of that accompanying base prospectus supplement and prospectus are incorporated by reference into this Common Stock Annex.
We had previously registered the offer and sale of up to $15,854,365,265.54 of our class A common stock under a prior prospectus supplement
annex (the “Prior Common Stock Annex”), the accompanying base prospectus supplement and prospectus. As of March 19, 2026, we have offered and sold 57,766,889 shares of class A common stock for aggregate offering proceeds of
$9,614,125,940.65 under the Prior Common Stock Annex, resulting in $6,240,239,324.89 of class A common stock remaining available for issuance under the Prior Common Stock Annex. We intend to continue to offer and sell class A common stock under the
Prior Common Stock Annex until all shares subject to the Prior Common Stock Annex have been sold in accordance with the terms thereof, following which we will offer and sell our class A common stock under this Common Stock Annex.
Our class A common stock is listed on The Nasdaq Global Select Market under the trading symbol “MSTR.” On March 20, 2026, the
last sale price of our class A common stock as reported on The Nasdaq Global Select Market was $135.66 per share.