Catalyst4 ups MapLight Therapeutics (MPLT) stake to 47.9% of shares

Rhea-AI Filing Summary

Catalyst4, Inc., together with Robert Brown, Ekemini Riley and Mark Vorsatz, reports beneficial ownership of 20,906,689 shares of MapLight Therapeutics, Inc. common stock, representing 47.9% of the issuer’s voting common stock outstanding as of July 27, 2026.

Catalyst4 holds these shares with sole voting and dispositive power, while the three individuals share voting and dispositive power over the same shares. Over the last 60 days, Catalyst4 acquired 1,209,225 shares in multiple open market transactions for an aggregate purchase price of approximately $15.3 million, funded from its working capital with no borrowed funds or other financing. These additional purchases constitute a material increase in the reporting group’s ownership percentage compared with an earlier Schedule 13D filed in November 2025.

Key Figures

Beneficial ownership: 20,906,689 shares Ownership percentage: 47.9 % Shares outstanding: 43,647,188 shares +2 more

5 metrics

Beneficial ownership 20,906,689 shares Shares of MapLight Therapeutics common stock beneficially owned by each reporting person

Ownership percentage 47.9 % Percent of class represented by 20,906,689 shares of voting common stock

Shares outstanding 43,647,188 shares Voting common stock outstanding as of July 27, 2026, used for percent-of-class calculation

Recent shares acquired 1,209,225 shares Shares acquired in the last 60 days in multiple open market transactions

Aggregate purchase price $15.3 million Approximate total paid for 1,209,225 recently acquired shares, including commissions

Key Terms

beneficial ownership, sole voting power, dispositive power, working capital, +1 more

5 terms

beneficial ownership financial

"update certain information with respect to the beneficial ownership of Voting Common Stock"

Beneficial ownership means the person or entity that actually enjoys the benefits of owning shares or other assets — such as receiving dividends, voting rights, or price gains — even if the legal title is held in another name. For investors it matters because knowing who truly controls and profits from a company reveals who can influence decisions, exposes potential conflicts of interest or hidden concentration of power, and affects transparency and risk in the stock.

sole voting power financial

"Number of Shares Beneficially Owned by Each Reporting Person With: Sole Voting Power 20,906,689.00"

Sole voting power is the exclusive right to cast votes attached to a shareholder’s stock without needing approval from anyone else. Like holding the only remote control for a TV, it lets that holder decide corporate matters such as board members, mergers, and policy changes, making it important to investors because it concentrates control and can strongly influence a company’s strategy and the value of its shares.

dispositive power financial

"Sole Dispositive Power 20,906,689.00"

Dispositive power is the authority to decide the final outcome of an asset, legal claim, contract, or corporate action — in effect the power to dispose of or resolve something. For investors it matters because whoever holds that authority can determine who gets paid, who controls an asset or vote, and how risks and returns are allocated; think of it like holding the key that lets you lock in the winner or loser in a deal.

working capital financial

"The source of funds for the purchase of such Shares of the Issuer was the working capital of Catalyst"

Working capital is the money a business has available to cover its daily expenses, like paying bills and buying supplies. It’s like the cash in your wallet that helps you handle everyday costs; having enough ensures the business can operate smoothly without running into money shortages.

open market transactions financial

"acquired 1,209,225 Shares of the Issuer in multiple open market transactions"

Open market transactions are the buying and selling of a company’s shares or other securities conducted on public exchanges or through the wider market rather than through private deals or negotiated placements. They matter to investors because these trades change supply and demand in real time—like shoppers affecting a store’s inventory—and so can move prices, signal management or investor sentiment, affect liquidity, and alter ownership stakes that influence future returns and risk.

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

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Available on EDGAR 08/03/2026 - 09:00 PM Accepted by SEC EDGAR 08/03/2026 - 09:00 PM Learn about SEC filing dates

FAQ

What stake in MapLight Therapeutics (MPLT) does Catalyst4 now report?

Catalyst4 and affiliated reporting persons now beneficially own 20,906,689 shares of MapLight Therapeutics common stock, representing 47.9% of the issuer’s voting common stock, based on 43,647,188 shares outstanding as of July 27, 2026.

How many MPLT shares were recently purchased and for how much?

Over the last 60 days, the reporting persons acquired 1,209,225 shares of MapLight Therapeutics in multiple open market transactions for an aggregate purchase price of approximately $15.3 million, including commissions, according to the disclosure.

Who directly holds the MPLT shares reported in this Schedule 13D/A?

Catalyst4, Inc. is the direct holder of the 20,906,689 shares and has sole voting and dispositive power. Robert Brown, Ekemini Riley and Mark Vorsatz share voting and dispositive power over the same shares as part of the reporting group.

How were Catalyst4’s recent MPLT share purchases financed?

The purchase of 1,209,225 shares for about $15.3 million was financed from the working capital of Catalyst4. No part of the price came from borrowed funds, loans, or other external financing arrangements.

Why was the Schedule 13D/A amendment filed for MapLight Therapeutics (MPLT)?

The amendment was filed because additional open market share purchases in the last 60 days created a material increase in the reporting group’s ownership percentage compared with a prior Schedule 13D filed on November 20, 2025.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 1)

MapLight Therapeutics, Inc.

(Name of Issuer)

Common Stock, $0.0001 par value per share

(Title of Class of Securities)

56565P103

(CUSIP Number)

Robert Brown
c/o Catalyst4, Inc., 555 Bryant Street #376
Palo Alto, CA, 94301
(650) 812-2614

Kenneth A, Clark
Wilson Sonsini Goodrich & Rosati, P.C., 650 Page Mill Road
Palo Alto, CA, 94304
650-493-9300

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

07/30/2026

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.

The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

schemaVersion:

SCHEDULE 13D

CUSIP Number(s): 56565P103

1

Name of reporting person

Catalyst4, Inc.

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 20,906,689.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 20,906,689.00
10	Shared Dispositive Power 0.00

11

Aggregate amount beneficially owned by each reporting person

20,906,689.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

47.9 %

14

Type of Reporting Person (See Instructions)

CO

Comment for Type of Reporting Person:

*The percent of class calculation is based on 43,647,188 shares of voting common stock of the Issuer outstanding as of July 27, 2026.

SCHEDULE 13D

CUSIP Number(s): 56565P103

1

Name of reporting person

Robert Brown

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

AF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 20,906,689.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 20,906,689.00

11

Aggregate amount beneficially owned by each reporting person

20,906,689.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

47.9 %

14

Type of Reporting Person (See Instructions)

IN

Comment for Type of Reporting Person:

*The percent of class calculation is based on 43,647,188 shares of voting common stock of the Issuer outstanding as of July 27, 2026.

SCHEDULE 13D

CUSIP Number(s): 56565P103

1

Name of reporting person

Ekemini Riley

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

AF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 20,906,689.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 20,906,689.00

11

Aggregate amount beneficially owned by each reporting person

20,906,689.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

47.9 %

14

Type of Reporting Person (See Instructions)

IN

Comment for Type of Reporting Person:

*The percent of class calculation is based on 43,647,188 shares of voting common stock of the Issuer outstanding as of July 27, 2026.

SCHEDULE 13D

CUSIP Number(s): 56565P103

1

Name of reporting person

Mark Vorsatz

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

AF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 20,906,689.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 20,906,689.00

11

Aggregate amount beneficially owned by each reporting person

20,906,689.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

47.9 %

14

Type of Reporting Person (See Instructions)

IN

Comment for Type of Reporting Person:

*The percent of class calculation is based on 43,647,188 shares of voting common stock of the Issuer outstanding as of July 27, 2026.

SCHEDULE 13D

Item 1.	Security and Issuer
(a)	Title of Class of Securities: Common Stock, $0.0001 par value per share
(b)	Name of Issuer: MapLight Therapeutics, Inc.
(c)	Address of Issuer's Principal Executive Offices: 800 Chesapeake Drive, Redwood City, CALIFORNIA , 94063.
Item 1 Comment: This Amendment No 1 to the Schedule 13D filed by the undersigned on November 20, 2025, is hereby filed to update certain information with respect to the beneficial ownership of Voting Common Stock (the "Shares") of MapLight Therapeutics, Inc., a Delaware company (the "Issuer"), by Catalyst4, Inc. ("Catalyst"), Robert Brown, Ekemini Riley and Mark Vorsatz. The foregoing individuals, together with Catalyst, are collectively referred to as the "Reporting Persons."
Item 3.	Source and Amount of Funds or Other Consideration
	Item 3 of the Schedule 13D is hereby amended and supplemented by adding the following information: During the last 60 days, the Reporting Persons acquired 1,209,225 Shares of the Issuer in multiple open market transactions for an aggregate purchase price of approximately $15.3 million, including commissions, as further disclosed in Item 5(c) of this Schedule 13D, which is incorporated by reference herein. The source of funds for the purchase of such Shares of the Issuer was the working capital of Catalyst. No part of the purchase price was represented by borrowed funds or other consideration obtained for the purpose of acquiring, holding, trading, or voting the securities, and there were no loans or financing arrangements involved in the transaction, with no other parties providing funds or consideration.
Item 5.	Interest in Securities of the Issuer
(c)	Item 5(c) of the Schedule 13D is hereby amended and supplemented by adding the following information: The transactions by the Reporting Persons in the Shares of the Issuer during the past 60 days are set forth in Annex A to this Schedule 13D. This Amendment is being filed because the additional purchases effected by the Reporting Person subsequent to the Schedule 13D filed by the Reporting Person on November 20, 2025 (the "Prior Filing"), represent a material increase to the Reporting Person's ownership percentage of the Issuer's outstanding Shares. The transactions set forth in Annex A include the additional purchases of Shares effected by Catalyst subsequent to the Prior Filing, which are identified in Annex A. The Reporting Persons note that such additional purchases were previously disclosed on a Form 4 filed by Catalyst with the Securities and Exchange Commission on July 30, 2026. Except as otherwise disclosed herein, the Reporting Persons have not effected any transaction in the Shares in the last 60 days.
Item 7.	Material to be Filed as Exhibits.
	Annex A: Schedule of Transactions

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Catalyst4, Inc.

Signature:	/s/ Robert Brown
Name/Title:	Robert Brown, President
Date:	08/03/2026

Robert Brown

Signature:	/s/ Robert Brown
Name/Title:	Robert Brown
Date:	08/03/2026

Ekemini Riley

Signature:	/s/ Ekemini Riley
Name/Title:	Ekemini Riley
Date:	08/03/2026

Mark Vorsatz

Signature:	/s/ Mark Vorsatz
Name/Title:	Mark Vorsatz
Date:	08/03/2026