Dropbox: Houston trust proposes $13.9M share sale

Three earlier sales for the trust are identified as 10b5-1 sales, dated from September 10, 2026, through October 12, 2026.

Available on EDGAR 11/02/2026 - 04:37 PM EST Accepted by SEC EDGAR 11/02/2026 - 04:37 PM EST Learn about SEC filing dates

Rhea-AI Filing Summary

Dropbox, Inc. (DBX) is the issuer in a Rule 144 notice for the Andrew Houston Revocable Trust's proposed sale of 383,800 common shares, with an aggregate market value of $13,912,750 and an approximate sale date of November 2, 2026. Morgan Stanley Smith Barney LLC is listed as broker, and the notice lists 150,561,680 shares outstanding. Andrew Houston signed the notice.

Key Figures

Proposed shares to be sold: 383,800 shares Aggregate market value: $13,912,750 Shares outstanding: 150,561,680 shares +3 more

6 metrics

Proposed shares to be sold 383,800 shares Approximate sale date November 2, 2026

Aggregate market value $13,912,750 Proposed sale by the Andrew Houston Revocable Trust

Shares outstanding 150,561,680 shares Issuer shares outstanding listed in the securities information

Earlier 10b5-1 sale shares 383,800 shares September 10, 2026

Earlier 10b5-1 sale shares 354,300 shares October 1, 2026

Earlier 10b5-1 sale shares 29,500 shares October 12, 2026

Key Terms

Rule 144, 10b5-1 Sales, Founders Shares

3 terms

Rule 144 regulatory

"See the definition of "person" in paragraph (a) of Rule 144."

Rule 144 is a U.S. securities regulation that sets conditions under which restricted or insider-held shares can be legally resold to the public, such as required holding periods, availability of public information, limits on how much can be sold at once, and certain filing requirements. For investors it matters because it determines when previously locked-up shares can enter the market — like a release valve that can increase supply, affect share price, and signal insider intent.

10b5-1 Sales regulatory

"10b5-1 Sales for THE ANDREW HOUSTON REVOCABLE TRUST"

10b5-1 sales are pre-arranged stock-trading plans that let company insiders automatically buy or sell shares according to a fixed schedule or formula, even if they later learn confidential information. Think of it as setting up an automatic thermostat for trades: it creates a clear, documented path that can protect insiders from insider-trading accusations and gives investors a signal about predictable insider activity—though it can also simply be a way for insiders to diversify or raise cash.

Founders Shares financial

"06/25/2007 | Founders Shares | Issuer"

Founders shares are a special block of a company’s stock originally given to the people who started the business; they often carry extra voting power or favorable terms compared with regular shares. For investors, these shares matter because they concentrate control and influence how future funding, ownership dilution, and decision-making will play out—think of founders shares as the steering wheel that can steer a company’s direction even as more passengers (investors) climb aboard.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

How many DBX shares is the Andrew Houston Revocable Trust proposing to sell?

The Andrew Houston Revocable Trust proposed to sell 383,800 Dropbox common shares, with an aggregate market value of $13,912,750 and an approximate sale date of November 2, 2026; Morgan Stanley Smith Barney LLC is listed as broker.

What earlier DBX share sales are listed for the Andrew Houston Revocable Trust?

The notice lists three 10b5-1 sales for the Andrew Houston Revocable Trust: 383,800 shares on September 10, 2026; 354,300 shares on October 1, 2026; and 29,500 shares on October 12, 2026.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK	0001734563
Filer CCC	XXXXXXXX
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer	Dropbox, Inc.
SEC File Number	001-38434
Address of Issuer	50 Hawthorne Street San Francisco CALIFORNIA 94105
Phone	4159307766
Name of Person for Whose Account the Securities are To Be Sold	ANDREW HOUSTON REVOCABLE TRUST
See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.
Relationship to Issuer	Director
Relationship to Issuer	Officer
Relationship to Issuer	10% Stockholder

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Common	Morgan Stanley Smith Barney LLC Executive Financial Services 1 New York Plaza 8th Floor New York NY 10004	383800	13912750.00	150561680	11/02/2026	NASDAQ

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Common	06/25/2007	Founders Shares	Issuer			383800	06/25/2007	N/A

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
10b5-1 Sales for THE ANDREW HOUSTON REVOCABLE TRUST 50 Hawthorne Street San Francisco CA 94105	Common	10/12/2026	29500	1035234.65
10b5-1 Sales for THE ANDREW HOUSTON REVOCABLE TRUST 50 Hawthorne Street San Francisco CA 94105	Common	10/01/2026	354300	12049815.22
10b5-1 Sales for THE ANDREW HOUSTON REVOCABLE TRUST 50 Hawthorne Street San Francisco CA 94105	Common	09/10/2026	383800	13439235.51

144: Remarks and Signature

Remarks
Date of Notice	11/02/2026
Date of Plan Adoption or Giving of Instruction, If Relying on Rule 10b5-1	06/11/2026
ATTENTION:
The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.
Signature	/s/ Andrew Houston
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)