Third Rock Ventures V, L.P. - 26 May 2026 Form 4 Insider Report for Rapport Therapeutics, Inc. (RAPP)

Reporting relationship
10%+ Owner
Issuer ticker
RAPP
Reported as of
26 May 2026
Net transaction value
-$743,753
Source evidence Original filing metadata and source links for verification. 4 source fields
SEC form
4
Accepted by SEC
28 May 2026, 16:15:04 UTC
Prior SEC filing
13 May 2026
Source filing
View source filing
Reporting owner 1 detail
Reporting owner signature
/s/ Kevin Gillis, Chief Operating Officer of TRV GP V, LLC, general partner of Third Rock Ventures GP V, L.P., general partner of Third Rock Ventures V, L.P.

Key filing fact

Third Rock Ventures V, L.P. filed Form 4 for Rapport Therapeutics, Inc. (RAPP) on 28 May 2026.

Key facts

  • This page summarizes Third Rock Ventures V, L.P.'s Form 4 filing for Rapport Therapeutics, Inc. (RAPP).
  • 1 reported transaction and 0 derivative rows are listed below.
  • Accepted by SEC: 28 May 2026, 16:15.

Change

  • Previous filing in this sequence was filed on 13 May 2026.
  • Current net transaction value: -$743,753.

Research use

  • This tells you what this filing adds before you inspect full transaction and derivative tables.
  • You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (6)

CIK 0001778071 Primary reporting owner

Third Rock Ventures V, L.P.

Relationship
10%+ Owner
Address
C/O THIRD ROCK VENTURES, LLC, 201 BROOKLINE AVE, SUITE 1401, BOSTON
Signature
/s/ Kevin Gillis, Chief Operating Officer of TRV GP V, LLC, general partner of Third Rock Ventures GP V, L.P., general partner of Third Rock Ventures V, L.P.
Signature date
28 May 2026
CIK 0001977498

Third Rock Ventures GP V, LP

Relationship
10%+ Owner
Address
201 BROOKLINE AVE, SUITE 1401, BOSTON
Signature
/s/ Kevin Gillis, Chief Operating Officer of TRV GP V, LLC, general partner of Third Rock Ventures GP V, L.P.
Signature date
28 May 2026
CIK 0001990717

TRV GP V, LLC

Relationship
10%+ Owner
Address
201 BROOKLINE AVE, SUITE 1401, BOSTON
Signature
/s/ Kevin Gillis, Chief Operating Officer of TRV GP V, LLC
Signature date
28 May 2026
CIK 0001931056

Third Rock Ventures VI, L.P.

Relationship
10%+ Owner
Address
C/O THIRD ROCK VENTURES, LLC, 201 BROOKLINE AVE, SUITE 1401, BOSTON
Signature
/s/ Kevin Gillis, Chief Operating Officer of TRV GP V, LLC, general partner of Third Rock Ventures GP V, L.P., general partner of Third Rock Ventures V, L.P.
Signature date
28 May 2026
CIK 0001977499

Third Rock Ventures GP VI, L.P.

Relationship
10%+ Owner
Address
201 BROOKLINE AVE, SUITE 1401, BOSTON
Signature
/s/ Kevin Gillis, Chief Operating Officer of TRV GP V, LLC, general partner of Third Rock Ventures GP V, L.P., general partner of Third Rock Ventures V, L.P.
Signature date
28 May 2026
CIK 0001990716

TRV GP VI, LLC

Relationship
10%+ Owner
Address
201 BROOKLINE AVE, SUITE 1401, BOSTON
Signature
/s/ Kevin Gillis, Chief Operating Officer of TRV GP V, LLC, general partner of Third Rock Ventures GP V, L.P., general partner of Third Rock Ventures V, L.P.
Signature date
28 May 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

RAPP transaction

Common Stock

Sale

Transaction value
$743,753
Shares
-18,572
Change %
-0.29%
Price
$40.05
Shares after
6,280,525
Date
26 May 2026
Ownership
Direct
Footnotes
F1, F2, F3
RAPP transaction

Common Stock

Sale

Transaction value
$743,753
Shares
-18,572
Change %
-0.29%
Price
$40.05
Shares after
6,280,525
Date
26 May 2026
Ownership
Direct
Footnotes
F1, F2, F3
RAPP transaction

Common Stock

Sale

Transaction value
$743,753
Shares
-18,572
Change %
-0.29%
Price
$40.05
Shares after
6,280,525
Date
26 May 2026
Ownership
Direct
Footnotes
F1, F2, F3
RAPP transaction

Common Stock

Sale

Transaction value
$743,753
Shares
-18,572
Change %
-0.29%
Price
$40.05
Shares after
6,280,525
Date
26 May 2026
Ownership
Direct
Footnotes
F1, F2, F3
RAPP transaction

Common Stock

Sale

Transaction value
$743,753
Shares
-18,572
Change %
-0.29%
Price
$40.05
Shares after
6,280,525
Date
26 May 2026
Ownership
Direct
Footnotes
F1, F2, F3
RAPP transaction

Common Stock

Sale

Transaction value
$743,753
Shares
-18,572
Change %
-0.29%
Price
$40.05
Shares after
6,280,525
Date
26 May 2026
Ownership
Direct
Footnotes
F1, F2, F3
RAPP holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
969,218
Date
26 May 2026
Ownership
By Third Rock Ventures VI, L.P.
Footnotes
F4
RAPP holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
969,218
Date
26 May 2026
Ownership
By Third Rock Ventures VI, L.P.
Footnotes
F4
RAPP holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
969,218
Date
26 May 2026
Ownership
By Third Rock Ventures VI, L.P.
Footnotes
F4
RAPP holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
969,218
Date
26 May 2026
Ownership
By Third Rock Ventures VI, L.P.
Footnotes
F4
RAPP holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
969,218
Date
26 May 2026
Ownership
By Third Rock Ventures VI, L.P.
Footnotes
F4
RAPP holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
969,218
Date
26 May 2026
Ownership
By Third Rock Ventures VI, L.P.
Footnotes
F4
* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Rule 10b5-1 trading plan

These transactions were reported as open-market trades under a Rule 10b5-1 plan. The plan lets an insider set trading instructions in advance, which can reduce the risk of trading while in possession of material nonpublic information.

Original filing language: transaction made pursuant to a contract, instruction, or written plan intended to satisfy Rule 10b5-1(c).

Explanation of responses 4 footnotes

Footnote F1

The reported transactions were effected pursuant to a Rule 10b5-1 trading plan dated November 21, 2025, previously adopted by the Reporting Person.

Footnote F2

The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $40.00 to $40.10, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (2).

Footnote F3

These shares are directly held by Third Rock Ventures V, L.P. ("TRV V"). The general partner of TRV V is Third Rock Ventures GP V, L.P. ("TRV GP V"). The general partner of TRV GP V is TRV GP V, LLC ("TRV GP V LLC"). Each of TRV GP V and TRV GP V LLC disclaims beneficial ownership of the shares except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that it is the beneficial owner of such shares.

Footnote F4

The shares are held directly by Third Rock Ventures VI, L.P. ("TRV VI"). The general partner of TRV VI is Third Rock Ventures GP VI, L.P. ("TRV GP VI"). The general partner of TRV GP VI is TRV GP VI, LLC ("TRV GP VI LLC"). Each of TRV GP VI, and TRV GP VI LLC, disclaims beneficial ownership of these shares except to the extent of its pecuniary interest therein, if any, and this report shall not be deemed an admission that it is the beneficial owner of such shares. Each of Reporting Persons disclaims the existence of a Section 13(d) "group" as between any TRV V related parties and any TRV VI related parties and this report shall not be deemed an admission that any of such parties is or may be part of such a group with any of the other parties.

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