CoastalSouth (COSO) CAO converts 4,000 RSUs, withholds 1,181 shares for taxes

Rhea-AI Filing Summary

CoastalSouth Bancshares, Inc. chief accounting officer Lauren M. Hemby exercised 4,000 Restricted Stock Units into an equal number of common shares on 2026-04-27. The RSUs converted into common stock on a one-for-one basis.

To cover tax obligations, 1,181 common shares were disposed of through a tax-withholding transaction at $25.59 per share, which is not an open-market sale. After these compensation-related transactions, Hemby directly holds 14,250 common shares and no remaining RSUs from this award.

Insider Trade Summary

4,000 shares exercised/converted

Mixed 3 txns

Insider Hemby Lauren M.

Role CHIEF ACCOUNTING OFFICER

Type	Security	Shares	Price	Value
Exercise	Restricted Stock Units	4,000	$0.00	--
Exercise	Common Stock	4,000	$0.00	--
Tax Withholding	Common Stock	1,181	$25.59	$30K

Holdings After Transaction: Restricted Stock Units — 0 shares (Direct, null); Common Stock — 14,250 shares (Direct, null)

Footnotes (1)

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Key Figures

RSUs exercised: 4,000 units Tax-withholding shares: 1,181 shares Tax-withholding price: $25.59/share +2 more

5 metrics

RSUs exercised 4,000 units Restricted Stock Units converted one-for-one into common stock on 2026-04-27

Tax-withholding shares 1,181 shares Common shares disposed of to cover tax liability at $25.59 per share

Tax-withholding price $25.59/share Value used for tax-withholding disposition of 1,181 common shares

Shares held after transactions 14,250 shares Direct common stock holdings following the Form 4 transactions

RSU balance after exercise 0 units Restricted Stock Units from this award remaining after 4,000-unit conversion

Key Terms

Restricted Stock Units, tax-withholding disposition, derivative exercise/conversion, derivative security

4 terms

Restricted Stock Units financial

"Restricted stock units ("RSU") convert into shares of the issuer's common stock on a one-for-one basis."

Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.

tax-withholding disposition financial

"transaction_action: "tax-withholding disposition" for 1,181 common shares at $25.59"

A tax-withholding disposition is an event or transaction—such as selling or transferring securities, exercising options, or receiving compensation—that triggers a requirement to hold back part of the payment and remit it to tax authorities. It matters to investors because it reduces the cash they receive immediately and can change the timing and amount of taxable income, like a cashier taking a portion of your sale proceeds to pay taxes before you get the rest.

derivative exercise/conversion financial

"transaction_action: "derivative exercise/conversion" describing the RSU conversion into common stock"

derivative security financial

"transaction_code_description: "Exercise or conversion of derivative security""

A derivative security is a financial contract whose value comes from the price or performance of something else, such as a stock, bond, commodity, or market index. For investors it acts like an insurance policy or a wager: it can be used to protect against losses, lock in prices, or amplify gains and losses, so it can change a portfolio’s risk and potential return without owning the underlying asset directly.

Form 4 Insider Transactions: What Each Field Means →

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).

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^*

Hemby Lauren M.

(Last) (First) (Middle)

400 GALLERIA PARKWAY

SUITE 1900

(Street)

ATLANTA GEORGIA 30339

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
CoastalSouth Bancshares, Inc. [ COSO ]

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	CHIEF ACCOUNTING OFFICER

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
04/27/2026

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
Common Stock	04/27/2026		M		4,000	A	$0	14,250	D
Common Stock	04/27/2026		F		1,181	D	$25.59	13,069	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
Restricted Stock Units	(1)	04/27/2026		M			4,000	04/27/2026	04/27/2026	Common Stock	4,000	(1)	0	D

Explanation of Responses:

1. Restricted stock units ("RSU") convert into shares of the issuer's common stock on a one-for-one basis.

	/s/ Lauren Hemby, Chief Accouting Officer	04/29/2026
	** 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)

FAQ

What did COSO executive Lauren M. Hemby report in this Form 4?

Lauren M. Hemby reported exercising 4,000 Restricted Stock Units into common stock and a related tax-withholding share disposition. These are compensation-related transactions, not open-market trades, and adjust her equity position in CoastalSouth Bancshares, Inc. without indicating a discretionary stock purchase or sale.

How many CoastalSouth (COSO) shares did the CAO acquire and dispose of?

Hemby acquired 4,000 CoastalSouth common shares by exercising Restricted Stock Units and disposed of 1,181 shares in a tax-withholding transaction. The tax-withholding covers liabilities and is not an open-market sale. Her direct common stock holdings increased and now total 14,250 shares.

Are the COSO transactions by Lauren M. Hemby open-market buys or sells?

No, the filing shows no open-market buys or sells. It reports a derivative exercise of 4,000 Restricted Stock Units into common shares and a tax-withholding disposition of 1,181 shares, which settles tax liabilities rather than representing a discretionary sale into the market.

How many CoastalSouth (COSO) shares does Lauren M. Hemby hold after these transactions?

After the reported transactions, Hemby directly holds 14,250 shares of CoastalSouth common stock. This figure reflects the RSU conversion adding 4,000 shares and the tax-withholding disposition of 1,181 shares recorded in the Form 4, as of the transaction date reported.

What are Restricted Stock Units in the COSO Form 4 filing?

Restricted Stock Units in this filing are equity awards that convert into common stock on a one-for-one basis. Hemby’s 4,000 RSUs converted into 4,000 CoastalSouth common shares on April 27, 2026, and the RSU balance from this specific award was reduced to zero afterward.