Solid Power (NASDAQ: SLDP) CTO has shares withheld to cover RSU taxes

Rhea-AI Filing Summary

Solid Power, Inc. Chief Technology Officer Joshua Buettner-Garrett reported a tax-related share disposition tied to equity compensation. On May 11, 2026, 58,082 shares of common stock were withheld at $3.075 per share to satisfy his tax obligation upon vesting of restricted stock units. After this withholding, he directly holds 1,405,361 shares of Solid Power common stock. This event reflects routine tax withholding and is not an open-market stock sale.

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	58,082	$3.075	$179K

Holdings After Transaction: Common Stock — 1,405,361 shares (Direct, null)

Footnotes (1)

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Key Figures

Shares withheld for taxes: 58,082 shares Valuation price per share: $3.075 per share Shares held after transaction: 1,405,361 shares

3 metrics

Shares withheld for taxes 58,082 shares Tax-withholding disposition on May 11, 2026

Valuation price per share $3.075 per share Value applied to withheld shares

Shares held after transaction 1,405,361 shares Direct holdings following tax withholding

Key Terms

tax-withholding disposition, restricted stock units, Form 4

3 terms

tax-withholding disposition financial

"transaction_action: "tax-withholding disposition" and code F description"

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.

restricted stock units financial

"tax obligation 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.

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)
05/11/2026

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	05/11/2026		F		58,082(1)	D	$3.075	1,405,361	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	05/12/2026
	** 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 insider transaction did SLDP’s CTO report on this Form 4?

Solid Power’s CTO, Joshua Buettner-Garrett, reported a tax-withholding disposition of shares. On vesting of restricted stock units, 58,082 common shares were withheld to cover his tax obligation rather than sold on the open market.

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

The filing shows 58,082 shares of Solid Power common stock were withheld. These shares satisfied the CTO’s tax obligation related to vesting restricted stock units, according to the footnote, and were not part of an open-market trade.

At what price were the SLDP shares valued for the tax-withholding disposition?

The withheld shares were valued at $3.075 per share. This price is used to determine the value of the 58,082 shares applied to the CTO’s tax obligation arising from the vesting of restricted stock units.

How many Solid Power (SLDP) shares does the CTO hold after this transaction?

Following the tax-withholding transaction, the CTO directly holds 1,405,361 shares of Solid Power common stock. This figure reflects his remaining position after 58,082 shares were withheld to satisfy his tax obligation on vested restricted stock units.

Was this SLDP insider transaction an open-market sale or purchase?

The transaction was not an open-market sale or purchase. It was classified as a tax-withholding disposition, where 58,082 shares were withheld by the issuer to cover the CTO’s tax liability from vesting restricted stock units.