Solid Power (SLDP) CTO uses 5,519 shares to pay RSU taxes, retains 1.4M

Rhea-AI Filing Summary

Solid Power, Inc. Chief Technology Officer Joshua Buettner-Garrett reported a routine tax-related share disposition. On the vesting of restricted stock units, 5,519 shares of common stock were withheld at $3.15 per share to satisfy his tax obligation.

After this withholding, he directly holds 1,399,842 shares of Solid Power common stock. This was not an open-market sale but an automatic mechanism tied to equity compensation vesting.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider Buettner-Garrett Joshua

Role Chief Technology Officer

Type	Security	Shares	Price	Value
Tax Withholding	Common Stock	5,519	$3.15	$17K

Holdings After Transaction: Common Stock — 1,399,842 shares (Direct, null)

Footnotes (1)

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Key Figures

Shares withheld for taxes: 5,519 shares Withholding price: $3.15 per share Shares held after transaction: 1,399,842 shares

3 metrics

Shares withheld for taxes 5,519 shares Common stock withheld for RSU tax obligation

Withholding price $3.15 per share Value used for tax-withholding disposition

Shares held after transaction 1,399,842 shares Direct common stock holdings post-withholding

Key Terms

restricted stock units, tax-withholding disposition, Form 4

3 terms

restricted stock units financial

"upon the vesting of restricted stock units."

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""

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.

Form 4 regulatory

"INSIDER FILING DATA (Form 4):"

Form 4 is a official document that company insiders, such as executives or major shareholders, file with regulators whenever they buy or sell company shares. It provides transparency about how those with inside knowledge are trading, helping investors see if insiders are confident in the company's prospects or may be selling for personal reasons. This information can influence investor decisions by revealing insiders' perspectives on the company's value.

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^*

Buettner-Garrett Joshua

(Last) (First) (Middle)

C/O SOLID POWER, INC.

486 S PIERCE AVE., SUITE E

(Street)

LOUISVILLE COLORADO 80027

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
Solid Power, Inc. [ SLDP ]

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Technology Officer

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/12/2026

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	05/12/2026		F		5,519(1)	D	$3.15	1,399,842	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 shares of the issuer's common stock withheld to satisfy the reporting person's tax obligation upon the vesting of restricted stock units.

	/s/ Kristen Gould, attorney-in-fact on behalf of Joshua Buettner-Garrett	05/13/2026
	** 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 Solid Power (SLDP) CTO Joshua Buettner-Garrett report in this Form 4?

He reported a tax-related share disposition, where 5,519 Solid Power common shares were withheld at $3.15 each to cover taxes due on vesting restricted stock units, leaving him with 1,399,842 directly held shares afterward.

Was the Solid Power (SLDP) CTO’s Form 4 a market sale of shares?

No, the Form 4 shows shares withheld for taxes, not an open-market sale. 5,519 shares were surrendered automatically to satisfy tax obligations triggered by restricted stock unit vesting, a common administrative step in equity compensation.

How many Solid Power (SLDP) shares were withheld for taxes in this filing?

A total of 5,519 common shares were withheld at $3.15 per share. These shares covered Chief Technology Officer Joshua Buettner-Garrett’s tax liability arising from the vesting of his restricted stock units, as disclosed in the Form 4 footnote.

How many Solid Power (SLDP) shares does the CTO hold after this Form 4 event?

Following the tax-withholding disposition, Joshua Buettner-Garrett directly holds 1,399,842 shares of Solid Power common stock. This figure reflects his position after 5,519 shares were used to satisfy tax obligations related to restricted stock unit vesting.

What does the tax-withholding disposition code F mean in the Solid Power (SLDP) Form 4?

Code F indicates shares were delivered to cover tax liability or exercise price. Here, 5,519 shares of common stock were withheld solely to satisfy the CTO’s tax obligation on restricted stock unit vesting, rather than sold in the open market.