Rapport Therapeutics (RAPP): Capital International Investors reports 6.1% beneficial stake

Rhea-AI Filing Summary

Capital International Investors, a division of Capital Research and Management Company and its investment management affiliates, reports amended beneficial ownership of common stock of Rapport Therapeutics, Inc..

CII is deemed to beneficially own 2,921,958 shares of Rapport Therapeutics common stock, representing 6.1% of the class, based on 47,826,929 shares believed to be outstanding. CII reports sole voting and sole dispositive power over 2,921,958 shares and no shared voting or dispositive power. The filing identifies SMALLCAP World Fund, Inc. as a person with rights to receive dividends or sale proceeds related to these securities.

Key Figures

Shares beneficially owned: 2,921,958 shares Percent of class: 6.1% Shares outstanding baseline: 47,826,929 shares +3 more

6 metrics

Shares beneficially owned 2,921,958 shares Common stock of Rapport Therapeutics beneficially owned by Capital International Investors

Percent of class 6.1% Portion of Rapport Therapeutics common stock class beneficially owned

Shares outstanding baseline 47,826,929 shares Shares of Rapport Therapeutics common stock believed to be outstanding

Sole voting power 2,921,958 shares Shares for which Capital International Investors has sole power to vote

Sole dispositive power 2,921,958 shares Shares for which Capital International Investors has sole power to dispose

Amendment date 06/30/2026 Dated as of June 30, 2026 in the Schedule 13G/A

Key Terms

beneficial owner, sole voting power, sole dispositive power, percent of class, +1 more

5 terms

beneficial owner financial

"CII is deemed to be the beneficial owner of 2,921,958 shares"

A beneficial owner is the person who ultimately owns or controls a financial asset or property, even if their name isn't directly on official documents. Think of it like someone who secretly holds the keys to a safe deposit box—others may appear to have access, but the true owner is the one who benefits from what's inside. Identifying beneficial owners helps ensure transparency and prevent illegal activities like money laundering or fraud.

sole voting power financial

"Sole power to vote or to direct the vote: 2,921,958"

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.

sole dispositive power financial

"Sole power to dispose or to direct the disposition of: 2,921,958"

Sole dispositive power is the exclusive legal authority to decide what happens to a security — for example, whether to sell, transfer, or retain shares — without needing anyone else’s permission. Investors care because it signals who truly controls the economic outcome of an investment: like holding the only key to a safe, the holder can realize gains or losses and may trigger regulatory reporting, insider rules, or influence over corporate ownership.

percent of class financial

"Percent of class: 6.1 %"

Percent of class is the portion of a specific category of securities—such as a company’s common shares, preferred shares, or a bond series—that takes part in or approves a corporate action (vote, consent, tender, etc.). Investors watch this number because it reveals how much support or opposition exists within that particular shareholder group; like counting how many members of a club back a proposal, it can determine whether a plan passes or how influence is distributed.

Schedule 13G/A regulatory

"Capital International Investors files on Schedule 13G/A as a holder over 5%"

A Schedule 13G/A is an amended public filing with the U.S. securities regulator that updates a previous Schedule 13G, disclosing when an individual or group holds a substantial (typically over 5%) stake in a company and is claiming a passive, non‑controlling intent. Investors monitor these updates because rising or falling holdings can signal changing confidence, potential future moves, or shifts in voting power — like watching a public ledger where large shareholders quietly adjust their positions.

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

See more from StockTitan in Google Search and AI answers. Adds StockTitan as a preferred source · opens Google

Add on Google Not now

Available on EDGAR 08/12/2026 - 10:29 AM Accepted by SEC EDGAR 08/12/2026 - 10:28 AM Learn about SEC filing dates

FAQ

What percentage of Rapport Therapeutics (RAPP) does Capital International Investors report owning?

Capital International Investors reports beneficial ownership of 6.1% of Rapport Therapeutics’ common stock, corresponding to 2,921,958 shares, based on 47,826,929 shares of common stock believed to be outstanding at the time of the filing.

How many Rapport Therapeutics (RAPP) shares does Capital International Investors control voting for?

Capital International Investors reports sole voting power over 2,921,958 shares of Rapport Therapeutics common stock and no shared voting power, indicating it alone can vote or direct the voting of these reported shares.

Who is the reporting person in this Schedule 13G/A for Rapport Therapeutics (RAPP)?

The reporting person is Capital International Investors, a division of Capital Research and Management Company and its investment management subsidiaries and affiliates, collectively providing investment management services under the Capital International Investors name.

What is the total number of Rapport Therapeutics (RAPP) shares outstanding used in this ownership calculation?

Capital International Investors’ 6.1% ownership is calculated using 47,826,929 shares of Rapport Therapeutics common stock that are believed to be outstanding, serving as the denominator for the reported percentage of the class.

Does any other party have rights to dividends or sale proceeds on the Rapport Therapeutics (RAPP) shares?

Yes. The filing identifies SMALLCAP World Fund, Inc. as a person that has the right to receive dividends from, or the proceeds from the sale of, the reported Rapport Therapeutics securities held on its behalf.

What dispositive power over Rapport Therapeutics (RAPP) shares does Capital International Investors report?

Capital International Investors reports sole dispositive power over 2,921,958 shares of Rapport Therapeutics common stock and no shared dispositive power, meaning it alone can decide how and when to dispose of these shares.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 1)

Rapport Therapeutics, Inc.

(Name of Issuer)

Common Stock

(Title of Class of Securities)

75383L102

(CUSIP Number)

06/30/2026

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

schemaVersion:

SCHEDULE 13G

CUSIP Number(s): 75383L102

1

Names of Reporting Persons

Capital International Investors

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 2,921,958.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 2,921,958.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

2,921,958.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

6.1 %

12

Type of Reporting Person (See Instructions)

IA

SCHEDULE 13G

Item 1.
(a)	Name of issuer: Rapport Therapeutics, Inc.
(b)	Address of issuer's principal executive offices: 99 HIGH STREET, SUITE 2100, BOSTON, MA 02110
Item 2.
(a)	Name of person filing: Capital International Investors
(b)	Address or principal business office or, if none, residence: 333 South Hope Street, 55th Fl, Los Angeles, CA 90071
(c)	Citizenship: N/A
(d)	Title of class of securities: Common Stock
(e)	CUSIP No.: 75383L102
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.	Ownership
(a)	Amount beneficially owned: 2,921,958 ** **Capital International Investors ("CII") is a division of Capital Research and Management Company ("CRMC"), as well as its investment management subsidiaries and affiliates Capital Bank and Trust Company, Capital International, Inc., Capital International Limited, Capital International Sarl, Capital International K.K., Capital Group Private Client Services, Inc., and Capital Group Investment Management Private Limited (together with CRMC, the "investment management entities"). CII's divisions of each of the investment management entities collectively provide investment management services under the name "Capital International Investors." CII is deemed to be the beneficial owner of 2,921,958 shares or 6.1% of the 47,826,929 shares believed to be outstanding.
(b)	Percent of class: 6.1 %
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 2,921,958
	(ii) Shared power to vote or to direct the vote: 0
	(iii) Sole power to dispose or to direct the disposition of: 2,921,958
	(iv) Shared power to dispose or to direct the disposition of: 0
Item 5.	Ownership of 5 Percent or Less of a Class.
	Not Applicable
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required. SMALLCAP World Fund, Inc.
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	Not Applicable
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11.

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.

Capital International Investors

Signature:	Aaron Espin
Name/Title:	Senior Vice President
Date:	07/29/2026