Stock-Based Compensation
On July 8, 2022, the board of directors approved the Proto Labs, Inc. 2022 Long-Term Incentive Plan, which was approved by the Company's shareholders at a Special Meeting of Shareholders on August 29, 2022, and subsequently amended and restated by the Company's shareholders at the Annual Meeting of Shareholders on May 23, 2024 (as amended and restated, and subsequently further amended, the 2022 Plan) to increase the number of shares available for issuance pursuant to awards under the 2022 Plan by an additional 430,000 shares, add a minimum vesting requirement, and extend the expiration date so that the term of the 2022 Plan runs for ten years from the date of the shareholder approval. On May 20, 2025, the Company's shareholders approved an amendment to the 2022 Plan to increase the number of shares available for issuance pursuant to awards under the 2022 Plan by an additional 296,000 shares. Under the 2022 Plan, the Company has the ability to grant stock options, stock appreciation rights (SARs), restricted stock, restricted stock units, other stock-based awards and cash incentive awards. Awards under the 2022 Plan have a maximum term of ten years from the date of grant. The compensation and talent committee may provide that the vesting or payment of any award will be subject to the attainment of specified performance measures in addition to the satisfaction of any continued service requirements and the compensation and talent committee will determine whether such measures have been achieved. The per-share exercise price of stock options and SARs granted under the 2022 Plan generally may not be less than the fair market value of a share of our common stock on the date of the grant.
The Company also has outstanding awards under the 2012 Long-Term Incentive Plan, as amended (the 2012 Plan), although the plan expired in February 2022 and no additional awards have since been or will be made under the 2012 Plan. The 2012 Plan provided the Company the ability to grant stock options, SARs, restricted stock, restricted stock units, other stock-based awards and cash incentive awards. Awards under the 2012 Plan that subsequently expired, were forfeited or cancelled, or settled in cash after August 29, 2022 became available for awards under the 2022 Plan.
On May 23, 2025, the Company granted one-time inducement awards (the Inducement Awards) within the meaning of the New York Stock Exchange Listed Company Manual Section 303A.08 to the Company's incoming Chief Executive Officer. The Inducement Awards were not granted under the 2022 Plan, but have the same terms and conditions as equity awards granted under the 2022 Plan, except as otherwise provided in the award agreements.
The Company’s 2012 Employee Stock Purchase Plan (ESPP) allows eligible employees to purchase a variable number of shares of the Company’s common stock at a discount through payroll deductions of up to 15 percent of their eligible compensation, subject to plan limitations. The ESPP provides for six-month offering periods with a single purchase period, and at the end of each offering period, employees are able to purchase shares at 85 percent of the lower of the fair market value of the Company’s common stock on the first trading day of the offering period or on the last trading day of the offering period. The Company determines the fair value stock-based compensation related to its ESPP in accordance with ASC 718 using the component measurement approach and the Black-Scholes standard option pricing model.
Employees purchased 111,844 and 141,743 shares of common stock under the ESPP at an average exercise price of $33.30 and $27.91 during 2025 and 2024, respectively. As of December 31, 2025, 490,306 shares remained available for future issuance under the ESPP.
The Company determines its stock-based compensation in accordance with ASC 718, which requires the measurement and recognition of compensation expense for all share-based payment awards made to employees and non-employee directors based on fair value.
Determining the appropriate fair value model and calculating the fair value of stock option grants requires the input of subjective assumptions. The Company uses the Black-Scholes option pricing model to value its stock option awards. Stock-based compensation expense is calculated using the Company’s best estimates, which involve inherent uncertainties and the application of management’s judgment. Significant estimates include its expected term and stock price volatility.
The expected term of stock options is estimated from the vesting period of the award and represents the weighted average period that the Company's stock options are expected to be outstanding. The Company estimates the volatility of its stock price based on the historic volatility of its common stock. The Company bases the risk-free interest rate that it uses in the Black-Scholes option pricing model on U.S. Treasury instruments with maturities similar to the expected term of the award being valued. The Company has never paid, and does not anticipate paying, any cash dividends in the foreseeable future and, therefore, the Company uses an expected dividend yield of zero in the option pricing model. The Company accounts for forfeitures as they occur. The Company recognizes stock-based compensation expense on a straight-line basis over the requisite service period.
The following table summarizes stock-based compensation expense for the years ended December 31, 2025, 2024 and 2023, respectively:
Year Ended December 31,
(in thousands)202520242023
Stock options and other$14,376 $15,691 $14,550 
Employee stock purchase plan1,353 1,308 1,439 
Total stock-based compensation expense$15,729 $16,999 $15,989 
Cost of revenue$1,792 $1,935 $1,840 
Operating expenses:
Marketing and sales3,317 3,112 3,426 
Research and development2,826 2,721 2,556 
General and administrative7,794 9,231 8,167 
Total stock-based compensation expense$15,729 $16,999 $15,989 
Stock Options
The following table provides the assumptions used in the Black-Scholes option pricing model for the years ended December 31, 2025, 2024 and 2023:
Year Ended December 31,
202520242023
Risk-free interest rate
3.80 - 4.17%
4.28 - 4.30%
3.55 - 4.55%
Expected life (years)6.256.25
2.00 - 6.25
Expected volatility
52.05 - 52.99%
50.62 - 53.17%
49.23 - 55.92%
Expected dividend yield0%0%0%
Weighted average grant date fair value$22.01$18.17$16.36
The following table summarizes stock option activity and the weighted average exercise price for the years ended December 31, 2025, 2024 and 2023:
Stock OptionsWeighted-
Average
Exercise Price
Options outstanding at January 1, 2023263,992$79.07 
Granted186,80433.36 
Exercised— 
Cancelled(63,635)62.44 
Expired(15,848)55.67 
Options outstanding at December 31, 2023371,31359.92 
Granted140,40533.44 
Exercised(1,936)32.13 
Cancelled(59,552)61.83 
Expired(5,094)67.78 
Options outstanding at December 31, 2024445,13651.34 
Granted147,66439.73 
Exercised(78,783)34.37 
Cancelled(137,449)40.09 
Expired(16,354)87.74 
Options outstanding at December 31, 2025360,214$52.94 
Exercisable at December 31, 2025186,198$67.55 
The outstanding options have a term of 10 years. For employees, options that have been granted become exercisable ratably over the vesting period, which is generally a four-year period, beginning on the first anniversary of the grant date, subject to the employee’s continuing service to the Company. For directors, options generally become exercisable in full on the first anniversary of the grant date.
The total intrinsic value of options exercised during the years ended December 31, 2025 and 2024, was $1.1 million and less than $0.1 million for each period respectively. There were no options exercised during the year ended December 31, 2023. The aggregate intrinsic value represents the cumulative difference between the fair market value of the underlying common stock and the option exercise prices.
For options outstanding at December 31, 2025, the weighted-average remaining contractual term was 6.4 years and the aggregate intrinsic value was $3.7 million. For options exercisable at December 31, 2025, the weighted-average remaining contractual term was 4.3 years and the aggregate intrinsic value was $1.3 million. Refer to the table below for additional information.
The following table summarizes information about stock options outstanding at December 31, 2025:
Options Outstanding, Vested and Expected to VestOptions Exercisable
Range of Exercise PricesNumber OutstandingWeighted Average
Remaining Contractual
Life
Weighted Average Exercise
Price ($)
Number ExercisableWeighted Average Exercise
Price ($)
$32.13 to $35.33
134,5007.2733.3163,58833.41
$35.34 to $43.97
116,0188.6939.1122,95239.37
$43.98 to $180.46
109,6962.8591.6299,65895.83
The fair value of share-based payment transactions is recognized in the Consolidated Statements of Comprehensive Income. As of December 31, 2025, there was $2.7 million of total unrecognized compensation cost related to unvested stock options, which is expected to be recognized over a weighted average period of 2.8 years. The total fair value of options vested was $2.3 million, $2.3 million and $1.8 million for the years ended December 31, 2025, 2024 and 2023, respectively.
Restricted Stock
The 2012 Plan provides for the award of restricted stock or restricted stock units. Restricted stock awards are share settled and restrictions lapse ratably over the vesting period, which is generally a four-year period, beginning on the first anniversary of the grant date, subject to the employee’s continuing service to the Company. For directors, restrictions generally lapse in full on the first anniversary of the grant date.
The following table summarizes restricted stock activity for the years ended December 31, 2025, 2024 and 2023:
Restricted
Stock Awards
Weighted-
Average
Grant Date
Fair Value
Per Share
Restricted stock at January 1, 2023478,596$70.36 
Granted410,68232.46 
Restrictions lapsed(137,053)79.61 
Forfeited(98,760)61.25 
Restricted stock at December 31, 2023653,46545.89 
Granted377,96133.50 
Restrictions lapsed(195,831)54.52 
Forfeited(72,334)38.40 
Restricted stock at December 31, 2024763,26138.25 
Granted312,95340.69 
Restrictions lapsed(233,612)40.19 
Forfeited(146,526)36.41 
Restricted stock at December 31, 2025696,076$39.07 
As of December 31, 2025, there was $16.6 million of unrecognized compensation expense related to unvested restricted stock, which is expected to be recognized over a weighted-average period of 2.7 years.
Performance Stock
Performance stock units (PSUs) are expressed in terms of a target number of PSUs, with anywhere between 0 percent and 200 percent of that target number capable of being earned and vesting at the end of a three-year performance period depending on the Company’s performance in the final year of the performance period and the award recipient’s continued employment. The Company’s outstanding PSUs at December 31, 2025 are based on market conditions and the related compensation cost is based on the fair value at grant date calculated using a Monte Carlo pricing model.
The following table summarizes performance stock activity for the years ended December 31, 2025, 2024 and 2023:
 Performance
Stock Awards
Weighted-
Average
Grant Date
Fair Value
Per Share
Performance stock at January 1, 202335,802$77.91 
Granted71,29557.79 
Restrictions lapsed— 
Performance change— 
Forfeited— 
Performance stock at December 31, 2023107,09774.08 
Granted79,43648.20 
Restrictions lapsed— — 
Performance change(2,772)227.14 
Forfeited(3,588)52.18 
Performance stock at December 31, 2024180,17360.75 
Granted 1
160,93959.61 
Restrictions lapsed(32,977)96.41
Performance change— 
Forfeited(76,176)56.74 
Performance stock at December 31, 2025231,959$56.21 
1 Includes a target number of 54,320 PSUs granted as part of the May 23, 2025, Inducement Awards, 27,160 of which have the same market condition as the PSUs granted under the 2022 Plan as described above, and 27,160 of which also include a performance condition with anywhere between 0 percent and 100 percent of the target number capable of being achieved during two six-month performance periods depending on revenue and then anywhere between 0 percent and 200 percent of such achieved PSUs capable of being earned and vesting during a three-year performance period depending on the Company's three-year cumulative total shareholder return performance relative to an index and the award recipient's continued employment.
As of December 31, 2025, there was $6.6 million of unrecognized compensation expense related to unvested performance stock, which is expected to be recognized over a weighted-average period of 2.0 years.
Employee Stock Purchase Plan
The following table presents the assumptions used to estimate the fair value of the ESPP during the years ended December 31, 2025, 2024 and 2023:
Year Ended December 31,
202520242023
Risk-free interest rate
3.67 - 4.29%
4.29 - 5.16%
4.60 - 5.16%
Expected life (months)6.006.006.00
Expected volatility
39.13 - 65.60%
30.97 - 65.60%
47.38 - 67.84%
Expected dividend yield0%0%0%

About Stock Compensation Disclosures

Stock-based compensation disclosures detail the equity awards granted to employees and executives — including stock options, restricted stock units (RSUs), and performance shares — along with the valuation methods and assumptions used to expense them. This section reveals the true cost of talent retention and the alignment between management incentives and shareholder interests.

Key signals: total unrecognized compensation expense and its expected recognition period signal future earnings headwinds from already-granted awards. For stock options, examine Black-Scholes assumptions — expected volatility, risk-free rate, and expected term — as understating any of these reduces reported compensation expense. Compare stock compensation expense as a percentage of revenue against peers to assess dilution cost. Watch vesting schedules for acceleration clauses tied to change-of-control events. Performance-based awards with undemanding targets may indicate weak governance. Add back stock compensation to operating cash flow to calculate a more conservative free cash flow figure.