STOCK TITAN

Solid Biosciences (SLDB) COO logs major PSU, RSU awards and tax sell

Filing Impact
(Moderate)
Filing Sentiment
(Negative)
Form Type
4

Rhea-AI Filing Summary

Solid Biosciences’ Chief Operating Officer David Howton reported multiple equity compensation events and a related share sale. On January 29, 2026, 79,341 performance stock units vested and converted into common stock, and he received 105,100 new restricted stock units plus an option for 210,200 shares at an exercise price of $6.60 per share, all vesting over four years.

On January 31, 2026, an additional 42,275 restricted stock units vested and converted into common stock. On February 2, 2026, he sold 37,771 shares of common stock at a weighted average price of $6.4369 solely to cover withholding taxes under a pre-established automatic sell-to-cover instruction, and continued to hold 116,753 shares directly afterward.

Positive

  • None.

Negative

  • None.
Insider Howton David T
Role Chief Operating Officer
Sold 37,771 shs ($243K)
Type Security Shares Price Value
Sale Common Stock 37,771 $6.4369 $243K
Exercise Restricted Stock Units 42,275 $0.00 --
Exercise Common Stock 42,275 $0.00 --
Exercise Performance Stock Units 79,341 $0.00 --
Grant/Award Employee Stock Option (Right to Buy) 210,200 $0.00 --
Grant/Award Restricted Stock Units 105,100 $0.00 --
Exercise Common Stock 79,341 $0.00 --
Holdings After Transaction: Common Stock — 116,753 shares (Direct); Restricted Stock Units — 126,825 shares (Direct); Performance Stock Units — 0 shares (Direct); Employee Stock Option (Right to Buy) — 210,200 shares (Direct)
Footnotes (1)
  1. Each performance stock unit ("PSUs") converts to common stock on a one-for-one basis. Each restricted stock unit ("RSUs") converts to common stock on a one-for-one basis. This sale was made to cover withholding taxes following the vesting of previously granted PSUs pursuant to a durable automatic sale instruction letter adopted by Mr. Howton on August 16, 2024 effecting the sell-to-cover election. The sale does not represent a discretionary trade by Mr. Howton. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $6.295 to $6.580, 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 range set forth in footnote (4) to this Form. The PSUs were granted on June 11, 2024 and provide for the vesting of 25% of the target number of underlying RSUs granted upon the achievement of each of four independent performance milestones predetermined by the Board ("Performance Milestones"), subject to the grantee's continued service with the Company (the "Approval Conditions"). The Performance Milestones are tied to the achievement of certain business objectives, as certified by the Board on specified evaluation dates, and are non-market and non-financial in nature. The performance criteria specified for the first Performance Milestone was determined to be met on January 29, 2026 (the "2026 Grant Date") resulting in the vesting of the PSUs as to 25% of the underlying shares. This option was granted on the 2026 Grant Date and vests over four years, with 25% of the original number of shares vesting on the first anniversary of the 2026 Grant Date and 2.0833% of the original number of shares monthly thereafter until the fourth such anniversary. The RSUs were granted on the 2026 Grant Date and vest over four years, with 25% of the original number of shares vesting on each anniversary of the 2026 Grant Date until the fourth such anniversary. On January 31, 2025 (the "2025 Grant Date"), the reporting person was granted 169,100 RSUs, with 25% of the original number of shares vesting on each anniversary of the 2025 Grant Date until the fourth such anniversary.
SEC Form 4
FORM 4 UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940
OMB APPROVAL
OMB Number: 3235-0287
Estimated average burden
hours per response: 0.5
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
X
Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.
1. Name and Address of Reporting Person*
Howton David T

(Last) (First) (Middle)
C/O SOLID BIOSCIENCES INC.
500 RUTHERFORD AVENUE, THIRD FLOOR

(Street)
CHARLESTOWN MA 02129

(City) (State) (Zip)
2. Issuer Name and Ticker or Trading Symbol
Solid Biosciences Inc. [ SLDB ]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
Director 10% Owner
X Officer (give title below) Other (specify below)
Chief Operating Officer
3. Date of Earliest Transaction (Month/Day/Year)
01/29/2026
4. If Amendment, Date of Original Filed (Month/Day/Year)
6. Individual or Joint/Group Filing (Check Applicable Line)
X Form filed by One Reporting Person
Form filed by More than One Reporting Person
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4)
Code V Amount (A) or (D) Price
Common Stock 01/29/2026 M 79,341 A (1) 112,249 D
Common Stock 01/31/2026 M 42,275 A (2) 154,254 D
Common Stock 02/02/2026 S 37,771(3) D $6.4369(4) 116,753 D
Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 6. Date Exercisable and Expiration Date (Month/Day/Year) 7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Performance Stock Units (1) 01/29/2026 M 79,341 (5) (5) Common Stock 79,341 $0.00 0 D
Employee Stock Option (Right to Buy) $6.6 01/29/2026 A 210,200 (6) 01/29/2036 Common Stock 210,200 $0.00 210,200 D
Restricted Stock Units (2) 01/29/2026 A 105,100 (7) (7) Common Stock 105,100 $0.00 105,100 D
Restricted Stock Units (2) 01/31/2026 M 42,275 (8) (8) Common Stock 42,275 $0.00 126,825 D
Explanation of Responses:
1. Each performance stock unit ("PSUs") converts to common stock on a one-for-one basis.
2. Each restricted stock unit ("RSUs") converts to common stock on a one-for-one basis.
3. This sale was made to cover withholding taxes following the vesting of previously granted PSUs pursuant to a durable automatic sale instruction letter adopted by Mr. Howton on August 16, 2024 effecting the sell-to-cover election. The sale does not represent a discretionary trade by Mr. Howton.
4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $6.295 to $6.580, 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 range set forth in footnote (4) to this Form.
5. The PSUs were granted on June 11, 2024 and provide for the vesting of 25% of the target number of underlying RSUs granted upon the achievement of each of four independent performance milestones predetermined by the Board ("Performance Milestones"), subject to the grantee's continued service with the Company (the "Approval Conditions"). The Performance Milestones are tied to the achievement of certain business objectives, as certified by the Board on specified evaluation dates, and are non-market and non-financial in nature. The performance criteria specified for the first Performance Milestone was determined to be met on January 29, 2026 (the "2026 Grant Date") resulting in the vesting of the PSUs as to 25% of the underlying shares.
6. This option was granted on the 2026 Grant Date and vests over four years, with 25% of the original number of shares vesting on the first anniversary of the 2026 Grant Date and 2.0833% of the original number of shares monthly thereafter until the fourth such anniversary.
7. The RSUs were granted on the 2026 Grant Date and vest over four years, with 25% of the original number of shares vesting on each anniversary of the 2026 Grant Date until the fourth such anniversary.
8. On January 31, 2025 (the "2025 Grant Date"), the reporting person was granted 169,100 RSUs, with 25% of the original number of shares vesting on each anniversary of the 2025 Grant Date until the fourth such anniversary.
/s/ Kimberly Cornwell as attorney-in-fact for David Tyronne Howton 02/02/2026
** Signature of Reporting Person Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transactions did SLDB’s COO report on this Form 4?

Solid Biosciences’ COO David Howton reported equity vesting, new grants, and a tax-related share sale. Performance stock units and restricted stock units converted into common stock, he received new options and RSUs, and sold shares only to cover withholding taxes under an automatic instruction.

How many Solid Biosciences shares did the COO sell, and at what price?

The COO sold 37,771 shares of Solid Biosciences common stock at a weighted average price of $6.4369. The sale occurred on February 2, 2026 and was executed in multiple trades within a price range from $6.295 to $6.580 per share.

Why did SLDB’s COO sell 37,771 shares of common stock?

The 37,771-share sale was made solely to cover withholding taxes after performance stock units vested. It followed a durable automatic sale instruction adopted in August 2024, meaning the transaction did not represent a discretionary trade by David Howton.

What new stock options did the Solid Biosciences COO receive?

On January 29, 2026, the COO received an option for 210,200 shares of common stock at a $6.60 exercise price. This option vests over four years, with 25% vesting on the first anniversary and the remainder vesting monthly until the fourth anniversary.

What restricted stock unit (RSU) awards are reported for SLDB’s COO?

The COO holds RSUs that convert one-for-one into common stock. He received 105,100 RSUs on January 29, 2026 that vest in four annual installments, and 169,100 RSUs granted January 31, 2025 vesting 25% on each anniversary of that 2025 grant date.

How many Solid Biosciences shares did the COO own after these transactions?

After the February 2, 2026 sale, the COO directly owned 116,753 shares of Solid Biosciences common stock. This figure reflects the net result of PSU and RSU conversions to common stock and the tax-related sale reported in this Form 4 filing.

What performance conditions triggered PSU vesting for SLDB’s COO?

PSUs vested when a predefined non-market, non-financial performance milestone was certified as achieved. On January 29, 2026, the board determined the first milestone under the June 11, 2024 PSU grant was met, causing 25% of the underlying performance stock units to vest and convert.