Under the 2013 Equity Incentive Plan, the Company granted 500,000 restricted common stock awards to an officer on September 5, 2018 (the "2018 Restricted Stock Award"). The 2018 Restricted Stock Award fully vested on March 28, 2024. The 2018 Restricted Stock Award was amortized on a straight-line basis over the requisite service period. The grant-date fair value of the 2018 Restricted Stock Award was determined using the closing price of Kingsway common stock on the date of grant. Total unamortized compensation expense related to unvested 2018 Restricted Stock Award at September 30, 2024 was zero.

Under the 2020 Equity Incentive Plan, the Company has granted restricted common stock awards to certain officers of the Company (the "2020 Plan Restricted Stock Awards"). The 2020 Plan Restricted Stock Awards vest according to a graded vesting schedule and shall become fully vested subject to the officers' continued employment through the applicable vesting dates. The 2020 Plan Restricted Stock Awards are amortized on a straight-line basis over the requisite service periods. The grant-date fair values of the 2020 Plan Restricted Stock Awards were determined using the closing price of Kingsway common stock on the date of grant. During the nine months ended September 30, 2024, 100,000 shares of the 2020 Plan Restricted Stock Awards became fully vested. Total unamortized compensation expense related to unvested 2020 Plan Restricted Stock Awards at September 30, 2024 was $2.0 million.

The following table summarizes the activity related to unvested 2020 Plan Restricted Stock Awards and 2018 Restricted Stock Award (collectively "Restricted Stock Awards") for the nine months ended September 30, 2024:

The unvested balance at September 30, 2024 in the table above is comprised of 448,964 shares of the 2020 Restricted Stock Awards and zero shares of the 2018 Restricted Stock Award.

Stock-based compensation expense related to the Restricted Stock Awards was $0.2 million for each of the three months ended September 30, 2024 and September 30, 2023 ($0.6 million and $0.7 million for the nine months ended September 30, 2024 and September 30, 2023, respectively).

Ravix LLC granted 199,000 restricted Class B common unit awards to an officer of Ravix pursuant to an agreement dated October 1, 2021 ("2021 Ravix RUA"). The 2021 Ravix RUA vests based on service and the achievement of criteria based on the internal rate of return ("IRR") of Ravix.

The grant-date fair value of the 2021 Ravix RUA was estimated using the Black-Scholes option pricing model, using the following assumptions: expected term of four years, expected volatility of 75%, expected dividend yield of zero, and risk-free interest rate of 0.93%.

On October 1, 2021, 83,333 units, representing one half of the service condition for the 2021 Ravix RUA, became fully vested. The remainder of the service condition vests according to a graded vesting schedule and shall become fully vested subject to the officer's continued employment through the applicable vesting dates.

On November 1, 2022, the Company modified the inputs related to the IRR portion of the 2021 Ravix RUA to be based on the combined internal rate of return of Ravix and CSuite. The modified portion of the awards was probable of vesting both immediately before and after the modification. As a result, the fair value of the award that is subject to the IRR was measured at the modification date and compared to the fair value of the modified portion of the award immediately prior to the modification, with the difference resulting in incremental compensation expense of less than $0.1 million. The incremental fair value was estimated using the Monte Carlo simulation model, using the following assumptions at the modification date: expected term of 2.92 years, expected volatility of 72% and risk-free interest rate of 4.44%; and the following assumptions prior to the modification: expected term of 2.92 years, expected volatility of 58% and risk-free interest rate of 4.44%.

During the nine months ended September 30, 2024, 15,625 units of the 2021 Ravix RUA became fully vested. At September 30, 2024 and December 31, 2023, there were 54,903 and 70,528 unvested units, respectively, of the 2021 Ravix RUA with a weighted-average grant date fair value of $3.08 per Class B common unit. Total unamortized compensation expense related to unvested 2021 Ravix RUA at September 30, 2024 was $0.1 million.

Stock-based compensation expense related to the 2021 Ravix RUA was less than $0.1 million for each of the three months ended September 30, 2024 and September 30, 2023 ($0.1 million for each of the nine months ended September 30, 2024 and September 30, 2023, respectively).

Pegasus LLC granted 75,000 restricted Class B common unit awards to an officer of SNS pursuant to an agreement dated November 18, 2022 ("SNS RUA"). The SNS RUA vests based on service and the achievement of criteria based on the IRR of SNS.

The grant-date fair value of the SNS RUA was estimated using the Monte Carlo simulation model, using the following assumptions: expected term of four years, expected volatility of 85% and risk-free interest rate of 4.09%.

On November 18, 2022, 25,000 units, representing one half of the service condition for the SNS RUA, became fully vested. The remainder of the service condition vests according to a graded vesting schedule and shall become fully vested subject to the officer's continued employment through the applicable vesting dates.

During the nine months ended September 30, 2024, 4,688 units of the SNS RUA vested. At September 30, 2024 and December 31, 2023, there were 38,542 and 43,229 unvested units, respectively, of the SNS RUA with a weighted-average grant date fair value of $5.74 and $5.84 per Class B common unit, respectively. Total unamortized compensation expense related to unvested SNS RUA at September 30, 2024 was $0.2 million.

Stock-based compensation expense related to the SNS RUA was less than $0.1 million for each of the three months ended September 30, 2024 and September 30, 2023 ($0.1 million for each of the nine months ended September 30, 2024 and September 30, 2023).

Vertical Market Solutions LLC, a subsidiary of the Company, granted 199,000 restricted Class B common unit awards to an officer of SPI pursuant to an agreement dated September 7, 2023 ("SPI RUA"). The SPI RUA vests based on service and the achievement of criteria based on the IRR of SPI.

The grant-date fair value of the SPI RUA was estimated using the Monte Carlo simulation model, using the following assumptions: expected term of five years, expected volatility of 59% and risk-free interest rate of 4.29%.

On September 7, 2023, 83,333 units, representing one half of the service condition for the SPI RUA, became fully vested. The remainder of the service condition vests according to a graded vesting schedule and shall become fully vested subject to the officer's continued employment through the applicable vesting dates.

During the nine months ended September 30, 2024, 20,833 units of the SPI RUA vested. At September 30, 2024 and December 31, 2023, there were 94,833 and 115,667 unvested units, respectively, of the SPI RUA with a weighted-average grant date fair value of $1.09 and $1.11 per Class B common unit, respectively. Total unamortized compensation expense related to unvested SPI RUA at September 30, 2024 was $0.1million.

Stock-based compensation expense related to the SPI RUA was less than $0.1 million and $0.1 million for the three months ended September 30, 2024 and September 30, 2023, respectively (less than $0.1 million and $0.1 million for the nine months ended September 30, 2024 and September 30, 2023, respectively).

DDI LLC granted 199,000 restricted Class B common unit awards to an officer of DDI pursuant to an agreement dated October 26, 2023 ("DDI RUA"). The DDI RUA vests based on service and the achievement of criteria based on the IRR of DDI.

The grant-date fair value of the DDI RUA was estimated using the Monte Carlo simulation model, using the following assumptions: expected term of five years, expected volatility of 57% and risk-free interest rate of 4.68%.

On October 26, 2023, 83,333 units, representing one half of the service condition for the DDI RUA, became fully vested. The remainder of the service condition vests according to a graded vesting schedule and shall become fully vested subject to the officer's continued employment through the applicable vesting dates.

During the nine months ended September 30, 2024, no units of the DDI RUA vested. At September 30, 2024 and December 31, 2023, there were 115,667 unvested units of the DDI RUA with a weighted-average grant date fair value of $4.16 per Class B common unit. Total unamortized compensation expense related to unvested DDI RUA at September 30, 2024 was $0.4 million.

Stock-based compensation expense related to the DDI RUA was less than $0.1 million and zero for the three months ended September 30, 2024 and September 30, 2023, respectively ($0.1 million and zero for the nine months ended September 30, 2024 and September 30, 2023, respectively).

SB LLC granted 199,000 restricted Class B common unit awards to an officer of Image Solutions pursuant to an agreement dated September 26, 2024 ("IS RUA"). The IS RUA vests based on service and the achievement of criteria based on the IRR of Image Solutions.

The grant-date fair value of the IS RUA was estimated using the Monte Carlo simulation model, using the following assumptions: expected term of five years, expected volatility of 51% and risk-free interest rate of 3.72%.

On September 26, 2024, 83,333 units, representing one half of the service condition for the IS RUA, became fully vested. The remainder of the service condition vests according to a graded vesting schedule and shall become fully vested subject to the officer's continued employment through the applicable vesting dates.

At September 30, 2024, there were 115,667 unvested units of the IS RUA with a weighted-average grant date fair value of $6.12 per Class B common unit. Total unamortized compensation expense related to unvested IS RUA at September 30, 2024 was $0.7 million.

Stock-based compensation expense related to the IS RUA was $0.6 million for each of the three months and nine months ended September 30, 2024.

Under the 2020 Equity Incentive Plan, the Company granted 265,000 stock options awards to certain employees of the Company during the second quarter of 2024 (the "Stock Options"). The Stock Options vest and become exercisable ratably over a five-year period and expire ten years after the date of grant. The Stock Options are amortized on a straight-line basis over the exercise period.

The following table summarizes the stock option activity during the nine months ended September 30, 2024:

The aggregate intrinsic value of stock options outstanding and exercisable is the difference between the September 30, 2024 market price for the Company's common shares and the exercise price of the options, multiplied by the number of options where the September 30, 2024 market price exceeds the exercise price.

Stock-based compensation expense related to the Stock Options was less than $0.1 million and $0.1 million for the three and nine months ended September 30, 2024, respectively. Total unamortized compensation expense related to unvested Stock Options at September 30, 2024 was $0.9 million.

The Company uses the Black-Scholes option pricing model to estimate the fair value of each option on the date of grant. The fair value of grants and the related assumptions used in the Black-Scholes pricing model for options granted during the nine months ended September 30, 2024 were as follows:

The risk-free rate was determined based on U.S. treasury yields that most closely approximated the option’s expected term. The dividend yield was determined based on the Company's dividend paying history. The expected volatility was calculated based on the weekly closing price of the Company's common stock over the expected life of the options. The expected term was determined by estimating a cost of equity for the Company to determine time to when the option would be at-the-money, and then adding that amount to the average time to vest.