Accelerant Holdings (ARX) COO executes 10b5-1 share sale and tax withholding

Rhea-AI Filing Summary

Accelerant Holdings executive Matthew David Sternberg, COO, Risk Exchange, sold 17,568 Class A Common Shares on July 27, 2026 at a weighted average price of $14.6406 per share under a Rule 10b5-1 trading plan adopted December 7, 2025.

Separately, on July 23, 2026, 3,910 shares were withheld at $13.77 per share to satisfy tax obligations upon settlement of vested Restricted Share Units, which was not an open-market sale.

Insider Trade Summary 10b5-1

Net Seller: 21,478 shares

Net Sell 2 txns

Insider Sternberg Matthew David

Role COO, Risk Exchange

Sold 17,568 shs ($257K)

Type	Security	Shares	Price	Value
Sale	Class A Common Shares F2, F3	17,568	$14.6406	$257K
Tax Withholding	Class A Common Shares F1	3,910	$13.77	$54K

Holdings After Transaction: Class A Common Shares — 596,482 shares (Direct)

Footnotes (3)

1. F1. Represents Class A Common Shares withheld, pursuant to Issuer policy, to satisfy tax withholding obligations upon the settlement of vested Restricted Share Units. Does not reflect a discretionary transaction nor an open market sale of securities.
2. F2. The sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 7, 2025.
3. F3. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $14.44 to $14.84, 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.

Key Figures

Shares sold: 17,568 shares Sale price: $14.6406 per share Shares withheld for taxes: 3,910 shares +2 more

5 metrics

Shares sold 17,568 shares Class A Common Shares sold on July 27, 2026 by COO Matthew David Sternberg

Sale price $14.6406 per share Weighted average price for the 17,568 shares sold, with trades from $14.44 to $14.84

Shares withheld for taxes 3,910 shares Class A shares withheld on July 23, 2026 to satisfy tax obligations on vested RSUs

Tax-withholding price $13.77 per share Per-share value used for the 3,910 shares withheld for tax obligations

Rule 10b5-1 plan adoption date December 7, 2025 Date Matthew David Sternberg adopted the trading plan governing the July 27, 2026 sale

Key Terms

Rule 10b5-1 trading plan, Restricted Share Units, weighted average price, tax withholding obligations

4 terms

Rule 10b5-1 trading plan regulatory

"The sales were effected pursuant to a Rule 10b5-1 trading plan"

A Rule 10b5-1 trading plan is a pre-arranged schedule that allows company insiders to buy or sell stock at specific times, even if they have inside information. It helps prevent accusations of unfair trading by making these transactions look planned and transparent, rather than sneaky or illegal.

Restricted Share Units financial

"upon the settlement of vested Restricted Share Units"

Restricted share units (RSUs) are a promise from a company to give an employee or service provider actual shares or cash equal to the shares after certain conditions are met, typically staying with the company for a set time or hitting performance targets. Think of them like a time-locked gift card that becomes usable only after you’ve earned it. For investors, RSUs matter because they align employee incentives with company performance and can increase the number of shares outstanding over time, diluting existing ownership and affecting earnings per share.

weighted average price financial

"The price reported in Column 4 is a weighted average price."

Weighted average price is the average price of a security where each trade or component is counted according to its size, so bigger trades pull the average more than smaller ones. Think of it like calculating the average cost of a grocery haul where items you bought more of have greater influence on the final per-item cost. Investors use it to understand the true average price paid or received, judge execution quality, and compare trading performance against market movement.

tax withholding obligations financial

"withheld, pursuant to Issuer policy, to satisfy tax withholding obligations"

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

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Form 4 Insider Transactions: What Each Field Means →

Available on EDGAR 07/27/2026 - 09:38 PM Accepted by SEC EDGAR 07/27/2026 - 09:38 PM Learn about SEC filing dates

FAQ

What insider stock transactions did Accelerant Holdings (ARX) COO Matthew David Sternberg report?

Matthew David Sternberg reported two transactions: an open-market sale of 17,568 Class A shares on July 27, 2026, and a tax-related withholding of 3,910 shares on July 23, 2026 tied to vested Restricted Share Units.

How many Accelerant Holdings (ARX) shares did the COO sell and at what price?

He sold 17,568 Class A Common Shares at a weighted average price of $14.6406 per share. Footnotes state the trades occurred in multiple transactions at prices ranging from $14.44 to $14.84, all under a pre-established trading plan.

Was the Accelerant Holdings (ARX) COO’s share sale made under a Rule 10b5-1 plan?

Yes. The Form 4 notes the July 27, 2026 sale was effected pursuant to a Rule 10b5-1 trading plan adopted by Matthew David Sternberg on December 7, 2025, indicating the transactions were pre-arranged rather than discretionary.

What is the nature of the 3,910 Accelerant Holdings (ARX) shares disposed of on July 23, 2026?

The 3,910 shares on July 23, 2026 were withheld to satisfy tax obligations upon settlement of vested Restricted Share Units. The footnote clarifies this was not a discretionary transaction nor an open-market sale of securities.

What were the tax-withholding transaction details for Accelerant Holdings (ARX) on July 23, 2026?

On July 23, 2026, 3,910 Class A shares were withheld at $13.77 per share. This withholding followed issuer policy to cover tax liabilities arising from the settlement of vested Restricted Share Units awarded to COO Matthew David Sternberg.

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^*

Sternberg Matthew David

(Last) (First) (Middle)

UNIT 106, WINDWARD 3

REGATTA OFFICE PARK, WEST BAY ROAD

(Street)

GRAND CAYMAN KY1-1108

(City) (State) (Zip)

CAYMAN ISLANDS

(Country)

2. Issuer Name and Ticker or Trading Symbol
Accelerant Holdings [ ARX ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	COO, Risk Exchange

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
07/23/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

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
Class A Common Shares	07/23/2026		F		3,910(1)	D	$13.77	614,050	D
Class A Common Shares	07/27/2026		S		17,568(2)	D	$14.6406(3)	596,482	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

Explanation of Responses:

1. Represents Class A Common Shares withheld, pursuant to Issuer policy, to satisfy tax withholding obligations upon the settlement of vested Restricted Share Units. Does not reflect a discretionary transaction nor an open market sale of securities.

2. The sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 7, 2025.

3. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $14.44 to $14.84, 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.

Remarks:

	/s/ Robert L. Villasenor, attorney-in-fact for Matthew David Sternberg	07/27/2026
	** 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.
* Form 4: SEC 1474 (03-26)