STEM executive vests PSUs, small tax share sale

STEM, INC. executive Matthew Tappin reported performance-based equity vesting and a small related share sale.

Rhea-AI Filing Summary

STEM, INC. executive Matthew Tappin reported performance-based equity vesting and a small related share sale. On June 30, 2026, he exercised performance stock units to acquire 7,750 shares of common stock at a conversion price of $0.00 per share, tied to achieving a volume-weighted average price of $17.60 over a defined period. On July 2, 2026, 996 shares were sold at $7.85 per share to cover tax liabilities from this settlement, described as a non-discretionary “sell to cover” transaction. Following these transactions, he directly held 9,577 common shares.

Insider Trade Summary

Exercise and sale activity reported; no spread calculated

Exercise and Sale 5 txns

Insider Tappin Matthew

Role President, Software Products

Sold 996 shs ($8K)

Approx. gross sale proceeds $8K

Approx. exercise cost $0.00

Type	Security	Shares	Price	Value
Sale	Common Stock, Par Value $0.0001 Per Share	996	$7.85	$8K
Exercise	Performance Stock Unit	2,750	$0.00	$0.00
Exercise	Performance Stock Unit	5,000	$0.00	$0.00
Exercise	Common Stock, Par Value $0.0001 Per Share	5,000	$7.81	$39K
Exercise	Common Stock, Par Value $0.0001 Per Share	2,750	$7.81	$21K

Holdings After Transaction: Performance Stock Unit — 7,750 contracts (Direct); Common Stock, Par Value $0.0001 Per Share — 9,577 shares (Direct)

Footnotes (4)

1. F1. Represents shares of common stock automatically sold to cover the reporting person's tax liability in connection with the settlement of PSUs on June 30, 2026. This "sell to cover" transaction does not represent a discretionary trade by the reporting person.
2. F2. Each performance stock unit ("PSU") represented a contingent right to receive one share of the Issuer's common stock if the volume-weighted average price of the Issuer's common stock for any consecutive sixty (60) trading-day period equaled or exceeded $17.60 (the "Performance Metric") during a performance period ending on June 30, 2028 (the "Performance Period").
3. F3. On June 30, 2025, the Reporting Person was granted 5,500 PSUs, 2,750 of which vested on June 30, 2026 following the Issuer's achievement of the Performance Metric during the Performance Period.
4. F4. On July 28, 2025, the Reporting Person was granted 10,000 PSUs, 5,000 of which vested on June 30, 2026 following the Issuer's achievement of the Performance Metric during the Performance Period.

Key Figures

Shares sold for tax: 996 shares at $7.85 Shares after transactions: 9,577 shares PSUs converted: 7,750 shares +4 more

7 metrics

Shares sold for tax 996 shares at $7.85 Automatic “sell to cover” on July 2, 2026

Shares after transactions 9,577 shares Direct common stock holdings following Form 4 transactions

PSUs converted 7,750 shares Performance stock units exercised into common stock on June 30, 2026

First PSU grant 5,500 PSUs Grant on June 30, 2025; 2,750 vested June 30, 2026

Second PSU grant 10,000 PSUs Grant on July 28, 2025; 5,000 vested June 30, 2026

Performance metric $17.60 VWAP Stock price hurdle for PSU vesting over sixty trading days

Performance period end June 30, 2028 End of performance period for PSU awards

Key Terms

Performance stock unit, volume-weighted average price, Performance Metric, Performance Period, +1 more

5 terms

Performance stock unit financial

"Each performance stock unit ("PSU") represented a contingent right to receive one share..."

A performance stock unit is a type of reward companies give to employees, usually managers, that depends on how well the company performs over time. If the company hits specific goals, the employee earns shares of stock, like earning a prize for reaching certain levels in a game. It motivates employees to work hard because their rewards are tied to the company's success.

volume-weighted average price financial

"if the volume-weighted average price of the Issuer's common stock for any consecutive sixty..."

Volume-weighted average price (VWAP) is the average price of a stock over a specific time period where each trade is weighted by the number of shares traded, so larger trades influence the average more than small ones. Investors and traders use VWAP as a reference point to judge whether trades are happening at relatively good or poor prices—like checking the average price paid for an item at a market where bulk purchases count more than single-item buys.

Performance Metric financial

"...equated or exceeded $17.60 (the "Performance Metric") during a performance period..."

Performance Period financial

"...during a performance period ending on June 30, 2028 (the "Performance Period")."

The performance period is the specific time span over which an investment’s results, an employee’s targets, or a fund’s returns are measured and judged. It matters to investors because the length and start/end of that window determine which gains or losses count toward performance fees, bonus payouts, or benchmark comparisons—much like timing a race decides who wins, the chosen period can change whether results look strong or weak.

sell to cover financial

"This "sell to cover" transaction does not represent a discretionary trade..."

Sell to cover is when a person who receives company stock through options or awards sells just enough shares immediately to pay required taxes, exercise costs, or fees, keeping the rest. Think of it like cashing part of a bonus to cover the tax bill so you can keep the remainder. For investors, it can create predictable small selling pressure and slightly change the number of shares actually held by insiders without increasing long‑term dilution.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What insider transactions did STEM (STEM) report for Matthew Tappin?

STEM reported that Matthew Tappin exercised performance stock units to acquire 7,750 common shares and sold 996 shares. The sale was solely to cover tax liabilities from the PSU settlement and was not a discretionary trade.

How many STEM (STEM) shares does Matthew Tappin hold after these Form 4 transactions?

After the reported transactions, Matthew Tappin directly holds 9,577 shares of STEM common stock. This reflects the net result of performance stock unit conversion into shares and the small, automatic “sell to cover” transaction for tax obligations.

What performance condition triggered Matthew Tappin’s STEM (STEM) performance stock units?

Each performance stock unit converted into one STEM share if the stock’s volume-weighted average price reached $17.60 over any consecutive sixty trading days. This condition was achieved within a performance period ending on June 30, 2028, enabling partial PSU vesting.

How many STEM (STEM) performance stock units vested for Matthew Tappin on June 30, 2026?

On June 30, 2026, 2,750 PSUs from a 5,500-unit grant and 5,000 PSUs from a 10,000-unit grant vested. In total, 7,750 performance stock units converted into an equal number of STEM common shares upon achievement of the performance condition.

Was Matthew Tappin’s sale of STEM (STEM) shares a discretionary insider sale?

The Form 4 footnote states the 996-share sale was automatically executed to cover tax liabilities from PSU settlement. It is characterized as a “sell to cover” transaction and explicitly described as not representing a discretionary trade by the reporting person.

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

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Accepted by SEC EDGAR 07/02/2026 - 06:57 PM Learn about SEC filing dates

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^*

Tappin Matthew

(Last) (First) (Middle)

1400 POST OAK BOULEVARD

SUITE 560

(Street)

HOUSTON TEXAS 77056

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
STEM, INC. [ STEM ]

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	President, Software Products

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
06/30/2026

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, Par Value $0.0001 Per Share	06/30/2026		M		5,000	A	$7.81	7,823	D
Common Stock, Par Value $0.0001 Per Share	06/30/2026		M		2,750	A	$7.81	10,573	D
Common Stock, Par Value $0.0001 Per Share	07/02/2026		S(1)		996	D	$7.85	9,577	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
Performance Stock Unit	(2)	06/30/2026		M			2,750	(3)	(3)	Common Stock, Par Value $0.0001 Per Share	2,750	$0	2,750	D
Performance Stock Unit	(2)	06/30/2026		M			5,000	(4)	(4)	Common Stock, Par Value $0.0001 Per Share	5,000	$0	5,000	D

Explanation of Responses:

1. Represents shares of common stock automatically sold to cover the reporting person's tax liability in connection with the settlement of PSUs on June 30, 2026. This "sell to cover" transaction does not represent a discretionary trade by the reporting person.

2. Each performance stock unit ("PSU") represented a contingent right to receive one share of the Issuer's common stock if the volume-weighted average price of the Issuer's common stock for any consecutive sixty (60) trading-day period equaled or exceeded $17.60 (the "Performance Metric") during a performance period ending on June 30, 2028 (the "Performance Period").

3. On June 30, 2025, the Reporting Person was granted 5,500 PSUs, 2,750 of which vested on June 30, 2026 following the Issuer's achievement of the Performance Metric during the Performance Period.

4. On July 28, 2025, the Reporting Person was granted 10,000 PSUs, 5,000 of which vested on June 30, 2026 following the Issuer's achievement of the Performance Metric during the Performance Period.

Remarks:

	/s/ Sarah Dunn, attorney-in-fact	07/02/2026
	** 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)