STOCK TITAN

Proto Labs (PRLB) COO sells 23,463 shares under 10b5-1 plan

Filing Impact
(Very High)
Filing Sentiment
(Negative)
Form Type
4

Rhea-AI Filing Summary

Proto Labs Inc Chief Operations Officer Michael R. Kenison reported a series of transactions in company common stock. On May 11–12, 2026, he sold a total of 23,463 shares in open-market sales at weighted average prices generally between about $67 and $71 per share, under a pre-arranged Rule 10b5-1 trading plan adopted August 15, 2025. Over the same two days, he exercised employee stock options covering 14,960 shares at exercise prices of $33.52, $33.84, $39.61 and $59.40 per share, converting derivative awards into common stock. Following these transactions, he directly holds 18,683 Proto Labs shares.

Positive

  • None.

Negative

  • None.
Insider Kenison Michael R.
Role Chief Operations Officer
Sold 23,463 shs ($1.64M)
Type Security Shares Price Value
Exercise Employee Stock Option (right to buy) 1,928 $0.00 --
Exercise Employee Stock Option (right to buy) 1,557 $0.00 --
Exercise Employee Stock Option (right to buy) 4,042 $0.00 --
Exercise Common Stock 1,928 $33.84 $65K
Exercise Common Stock 1,557 $39.61 $62K
Exercise Common Stock 4,042 $59.40 $240K
Sale Common Stock 1,613 $67.5807 $109K
Sale Common Stock 4,198 $68.6971 $288K
Sale Common Stock 3,576 $69.7823 $250K
Sale Common Stock 6,643 $70.2958 $467K
Exercise Employee Stock Option (right to buy) 3,756 $0.00 --
Exercise Employee Stock Option (right to buy) 3,677 $0.00 --
Exercise Common Stock 3,756 $33.84 $127K
Exercise Common Stock 3,677 $33.52 $123K
Sale Common Stock 7,433 $70.2612 $522K
Holdings After Transaction: Employee Stock Option (right to buy) — 1,928 shares (Direct, null); Common Stock — 29,114 shares (Direct, null)
Footnotes (1)
  1. These shares were acquired and sold pursuant to Reporting Person's 10b5-1 plan adopted August 15, 2025. Reflects the weighted average price of 7,433 shares of common stock of Proto Labs Inc. sold by the reporting person in multiple transactions on May 11, 2026, with sale prices ranging from $70.00 to $70.57 per share. The reporting person undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. Reflects the weighted average price of 1,613 shares of common stock of Proto Labs Inc. sold by the reporting person in multiple transactions on May 12, 2026, with sale prices ranging from $67.06 to $68.05 per share. The reporting person undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. Reflects the weighted average price of 4,198 shares of common stock of Proto Labs Inc. sold by the reporting person in multiple transactions on May 12, 2026, with sale prices ranging from $68.10 to $69.0425 per share. The reporting person undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. Reflects the weighted average price of 3,576 shares of common stock of Proto Labs Inc. sold by the reporting person in multiple transactions on May 12, 2026, with sale prices ranging from $69.13 to $70.1181 per share. The reporting person undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. Reflects the weighted average price of 6,643 shares of common stock of Proto Labs Inc. sold by the reporting person in multiple transactions on May 12, 2026, with sale prices ranging from $70.13 to $70.57 per share. The reporting person undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. 25% of shares subject to the award will vest on February 13, 2024, and on each February 13th thereafter until all shares subject to the award are fully vested. 25% of shares subject to the award will vest on February 13, 2025, and on each February 13th thereafter until all shares subject to the award are fully vested. 25% of shares subject to the award will vest on February 25, 2026, and on each February 25th thereafter until all shares subject to the award are fully vested. 25% of shares subject to the award will vest on February 13, 2023, and on each February 13th thereafter until all shares subject to the award are fully vested.
Shares sold 23,463 shares Total common stock sold May 11–12, 2026
Options exercised 14,960 shares Total shares from option exercises May 11–12, 2026
Post-trade holdings 18,683 shares Common shares directly owned after latest transaction
Sale price example $70.2612 per share Weighted average price for 7,433 shares sold May 11, 2026
Sale price range example $70.00–$70.57 per share Price range for 7,433 shares sold May 11, 2026
Exercise price (option) $59.40 per share Exercise price for 4,042 options into common stock
Lower exercise price $33.52 per share Exercise price for 3,677 options into common stock
10b5-1 plan financial
"These shares were acquired and sold pursuant to Reporting Person's 10b5-1 plan adopted August 15, 2025."
A 10b5-1 plan is a pre-arranged strategy that allows company insiders to buy or sell their shares at predetermined times and prices, even while they are aware of confidential information. It acts like a scheduled appointment for trading, helping ensure transactions happen transparently and legally, which can reassure investors that trades are not based on insider knowledge.
weighted average price financial
"Reflects the weighted average price of 7,433 shares of common stock of Proto Labs Inc. sold"
Weighted average price is the average price of a security where each trade or component is counted according to its size, so bigger trades pull the average more than smaller ones. Think of it like calculating the average cost of a grocery haul where items you bought more of have greater influence on the final per-item cost. Investors use it to understand the true average price paid or received, judge execution quality, and compare trading performance against market movement.
Employee Stock Option (right to buy) financial
"security_title": "Employee Stock Option (right to buy)""
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.
vesting financial
"25% of shares subject to the award will vest on February 13, 2024, and on each February 13th thereafter"
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.
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).
X
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*
Kenison Michael R.

(Last)(First)(Middle)
5540 PIONEER CREEK DRIVE

(Street)
MAPLE PLAIN MINNESOTA 55359

(City)(State)(Zip)

UNITED STATES

(Country)
2. Issuer Name and Ticker or Trading Symbol
Proto Labs Inc [ PRLB ]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
Director10% Owner
XOfficer (give title below)Other (specify below)
Chief Operations 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)
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 Stock05/11/2026M(1)3,756A$33.8430,942D
Common Stock05/11/2026M(1)3,677A$33.5234,619D
Common Stock05/11/2026S(1)7,433D$70.2612(2)27,186D
Common Stock05/12/2026M1,928A$33.8429,114D
Common Stock05/12/2026M1,557A$39.6130,671D
Common Stock05/12/2026M4,042A$59.434,713D
Common Stock05/12/2026S1,613D$67.5807(3)33,100D
Common Stock05/12/2026S4,198D$68.6971(4)28,902D
Common Stock05/12/2026S3,576D$69.7823(5)25,326D
Common Stock05/12/2026S6,643D$70.2958(6)18,683D
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
Employee Stock Option (right to buy)$33.8405/11/2026M(1)3,756 (7)02/14/2033Common Stock3,756$03,856D
Employee Stock Option (right to buy)$33.5205/11/2026M(1)3,677 (8)02/13/2034Common Stock3,677$03,778D
Employee Stock Option (right to buy)$33.8405/12/2026M1,928 (7)02/14/2033Common Stock1,928$01,928D
Employee Stock Option (right to buy)$39.6105/12/2026M1,557 (9)02/25/2035Common Stock1,557$04,674D
Employee Stock Option (right to buy)$59.405/12/2026M4,042 (10)02/13/2032Common Stock4,042$00D
Explanation of Responses:
1. These shares were acquired and sold pursuant to Reporting Person's 10b5-1 plan adopted August 15, 2025.
2. Reflects the weighted average price of 7,433 shares of common stock of Proto Labs Inc. sold by the reporting person in multiple transactions on May 11, 2026, with sale prices ranging from $70.00 to $70.57 per share. The reporting person undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.
3. Reflects the weighted average price of 1,613 shares of common stock of Proto Labs Inc. sold by the reporting person in multiple transactions on May 12, 2026, with sale prices ranging from $67.06 to $68.05 per share. The reporting person undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.
4. Reflects the weighted average price of 4,198 shares of common stock of Proto Labs Inc. sold by the reporting person in multiple transactions on May 12, 2026, with sale prices ranging from $68.10 to $69.0425 per share. The reporting person undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.
5. Reflects the weighted average price of 3,576 shares of common stock of Proto Labs Inc. sold by the reporting person in multiple transactions on May 12, 2026, with sale prices ranging from $69.13 to $70.1181 per share. The reporting person undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.
6. Reflects the weighted average price of 6,643 shares of common stock of Proto Labs Inc. sold by the reporting person in multiple transactions on May 12, 2026, with sale prices ranging from $70.13 to $70.57 per share. The reporting person undertakes to provide upon request by the U.S. Securities and Exchange Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.
7. 25% of shares subject to the award will vest on February 13, 2024, and on each February 13th thereafter until all shares subject to the award are fully vested.
8. 25% of shares subject to the award will vest on February 13, 2025, and on each February 13th thereafter until all shares subject to the award are fully vested.
9. 25% of shares subject to the award will vest on February 25, 2026, and on each February 25th thereafter until all shares subject to the award are fully vested.
10. 25% of shares subject to the award will vest on February 13, 2023, and on each February 13th thereafter until all shares subject to the award are fully vested.
Remarks:
/s/ W. Morgan Burns, Attorney-in-Fact05/13/2026
** 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 transactions did Proto Labs (PRLB) report for Michael R. Kenison?

Proto Labs reported that Chief Operations Officer Michael R. Kenison sold 23,463 common shares and exercised options for 14,960 shares on May 11–12, 2026. These were open-market sales and derivative exercises disclosed in a Form 4 insider trading report.

How many Proto Labs (PRLB) shares did the COO sell and at what prices?

The COO sold 23,463 Proto Labs common shares in multiple open-market transactions. Weighted average sale prices ranged roughly from $67 to just over $70 per share, with detailed price ranges for each trade bucket provided in the Form 4 footnotes.

What stock options did the Proto Labs (PRLB) COO exercise in this filing?

Michael R. Kenison exercised employee stock options covering 14,960 shares of Proto Labs common stock. The options had exercise prices of $33.52, $33.84, $39.61 and $59.40 per share, converting derivative awards into directly held common shares across May 11–12, 2026.

Were the Proto Labs (PRLB) COO’s stock sales made under a 10b5-1 plan?

Yes. A footnote states the Proto Labs COO’s shares were acquired and sold pursuant to a Rule 10b5-1 trading plan adopted on August 15, 2025. Such pre-arranged plans schedule trades in advance, reducing the significance of short-term market timing.

How many Proto Labs (PRLB) shares does the COO hold after these transactions?

After the reported sales and option exercises, Michael R. Kenison directly holds 18,683 Proto Labs common shares. This post-transaction holding is disclosed in the Form 4 as the total shares beneficially owned directly following the latest reported transaction.

What do the weighted average price footnotes mean in the Proto Labs (PRLB) Form 4?

The weighted average price footnotes explain that each reported sale aggregates multiple trades within a price range. For each share group, the Form 4 lists a single average price and notes that detailed trade-by-trade prices are available on request from Proto Labs, regulators or shareholders.