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Solid Power (SLDP) director Erik Anderson receives 44,133 RSU equity grant

Filing Impact
(Neutral)
Filing Sentiment
(Neutral)
Form Type
4

Rhea-AI Filing Summary

ANDERSON ERIK J reported acquisition or exercise transactions in this Form 4 filing.

Solid Power, Inc. director Erik J. Anderson reported an equity compensation grant in the form of restricted stock units. He received 44,133 RSUs, each representing one share of common stock at a grant price of $0.00 per share. These RSUs vest on the earlier of the first anniversary of the grant date or the day before Solid Power’s next annual stockholder meeting, subject to his continued service. After this award, he holds 304,503 shares directly and 157,617 shares indirectly through WestRiver Management, LLC.

Positive

  • None.

Negative

  • None.
Insider ANDERSON ERIK J
Role null
Type Security Shares Price Value
Grant/Award Common Stock 44,133 $0.00 --
holding Common Stock -- -- --
Holdings After Transaction: Common Stock — 304,503 shares (Direct, null); Common Stock — 157,617 shares (Indirect, By WestRiver Management, LLC)
Footnotes (1)
  1. Represents restricted stock units, which upon vesting of the unit, represent the right to receive one share of the issuer's common stock. The restricted stock units vest upon the earlier of: (i) the first anniversary of the grant date or (ii) the day before the issuer's next annual meeting of stockholders following the grant date, in each case, subject to the reporting person continuing to be a service provider (as defined in the Solid Power, Inc. 2021 Equity Incentive Plan) through such vesting date. Represents 157,617 shares owned directly by WestRiver Management, of which the reporting person is the sole member and sole manager.
RSU grant size 44,133 units Restricted stock units awarded to director on May 20, 2026
Grant price $0.00 per share Price per share for RSU equity compensation grant
Direct holdings after grant 304,503 shares Common stock directly owned following the RSU award
Indirect holdings 157,617 shares Common stock held indirectly through WestRiver Management, LLC
restricted stock units financial
"Represents restricted stock units, which upon vesting of the unit, represent the right to receive one share of the issuer's common stock."
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.
vesting financial
"The restricted stock units vest upon the earlier of: (i) the first anniversary of the grant date or (ii) the day before the issuer's next annual meeting..."
Vesting is the process by which you earn full ownership of something, like company stock or a retirement benefit, over time. It’s like earning the right to keep a gift piece by piece the longer you stay with a company, making sure employees stay committed before they receive all the benefits.
service provider financial
"subject to the reporting person continuing to be a service provider (as defined in the Solid Power, Inc. 2021 Equity Incentive Plan) through such vesting date."
Equity Incentive Plan financial
"as defined in the Solid Power, Inc. 2021 Equity Incentive Plan"
An equity incentive plan is a program that gives employees, executives or directors the right to receive company stock or options to buy stock as part of their pay. Think of it as offering slices of future company profit to motivate people to boost long‑term performance; for investors it matters because it can align employee goals with shareholder value but also increases the number of shares outstanding, which can dilute existing ownership.
indirect ownership financial
"Represents 157,617 shares owned directly by WestRiver Management, of which the reporting person is the sole member and sole manager."
SEC Form 4
FORM 4UNITED 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*
ANDERSON ERIK J

(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)
XDirector10% Owner
Officer (give title below)Other (specify below)
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
05/20/2026
6. Individual or Joint/Group Filing (Check Applicable Line)
XForm 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)
CodeVAmount(A) or (D)Price
Common Stock05/20/2026A44,133(1)A$0304,503D
Common Stock157,617IBy WestRiver Management, LLC(2)
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)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares
Explanation of Responses:
1. Represents restricted stock units, which upon vesting of the unit, represent the right to receive one share of the issuer's common stock. The restricted stock units vest upon the earlier of: (i) the first anniversary of the grant date or (ii) the day before the issuer's next annual meeting of stockholders following the grant date, in each case, subject to the reporting person continuing to be a service provider (as defined in the Solid Power, Inc. 2021 Equity Incentive Plan) through such vesting date.
2. Represents 157,617 shares owned directly by WestRiver Management, of which the reporting person is the sole member and sole manager.
/s/ Kristen Gould, attorney-in-fact on behalf of Erik J. Anderson05/21/2026
** Signature of Reporting PersonDate
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 Solid Power (SLDP) director Erik Anderson report?

Erik Anderson reported receiving a grant of 44,133 restricted stock units for Solid Power common stock. These RSUs are compensation, not a market purchase, and increase his equity exposure to the company subject to future vesting conditions tied to continued service.

How many Solid Power (SLDP) shares does Erik Anderson hold after this Form 4?

After the reported transactions, Erik Anderson holds 304,503 Solid Power shares directly. He also has an indirect holding of 157,617 shares through WestRiver Management, LLC, where he is the sole member and sole manager, reflecting both personal and entity-related positions.

What are the vesting terms for Erik Anderson’s 44,133 RSUs in Solid Power (SLDP)?

The 44,133 restricted stock units vest on the earlier of the first anniversary of the grant date or the day before Solid Power’s next annual stockholder meeting, provided Erik Anderson continues as a service provider under the company’s 2021 Equity Incentive Plan.

Is Erik Anderson’s Form 4 transaction in Solid Power (SLDP) an open-market buy or sell?

No, the Form 4 shows a grant of 44,133 restricted stock units at a price of $0.00 per share. This is an equity compensation award, not an open-market purchase or sale, and therefore does not reflect a discretionary trading decision in the public market.

How are Erik Anderson’s indirect Solid Power (SLDP) holdings structured?

The filing shows 157,617 Solid Power common shares owned by WestRiver Management, LLC. Erik Anderson is the sole member and sole manager of WestRiver Management, so those shares are reported as indirectly owned, separate from his directly held 304,503 shares.