The Company has had a nonqualified incentive stock option plan (the “BancFirst ISOP”) since May 1986. At December 31, 2020, there were 190,500 shares available for future grants. The BancFirst ISOP will terminate on December 31, 2024, if not extended. The options vest and are exercisable beginning four years from the date of grant at the rate of 25% per year for four years. Options expire at the end of fifteen years from the date of grant. The option price must be no less than 100% of the fair value of the stock relating to such option at the date of grant.

The Company has had the BancFirst Corporation Non-Employee Directors’ Stock Option Plan (the “BancFirst Directors’ Stock Option Plan”) since June 1999. Each non-employee director is granted an option for 10,000 shares. At December 31, 2020, there were 30,000 shares available for future grants. The BancFirst Directors’ Stock Option Plan will terminate on December 31, 2024, if not extended. The options vest and are exercisable beginning one year from the date of grant at the rate of 25% per year for four years, and expire at the end of fifteen years from the date of grant. The option price must be no less than 100% of the fair value of the stock relating to such option at the date of grant.

The Company currently uses newly issued shares for stock option exercises, but reserves the right to use shares purchased under the Company’s Stock Repurchase Program (the “SRP”) in the future.

The following table is a summary of the activity under both the BancFirst ISOP and the BancFirst Directors’ Stock Option Plan:

						Wgtd. Avg.
				Wgtd. Avg.		Remaining	Aggregate
				Exercise		Contractual	Intrinsic
	Options			Price		Term	Value
	(Dollars in thousands, except option data)
Year Ended December 31, 2020
Outstanding at December 31, 2019		1,257,730		$	32.70
Options granted		171,000			48.89
Options exercised		(76,650	)		20.53
Options canceled, forfeited, or expired		(9,000	)		58.26
Outstanding at December 31, 2020		1,343,080			35.28	8.61Yrs	$	31,453
Exercisable at December 31, 2020		710,330			25.06	6.94Yrs	$	23,894
Year Ended December 31, 2019
Outstanding at December 31, 2018		1,216,700		$	28.48
Options granted		178,500			56.87
Options exercised		(107,470	)		21.23
Options canceled, forfeited, or expired		(30,000	)		46.42
Outstanding at December 31, 2019		1,257,730			32.70	9.28Yrs	$	37,408
Exercisable at December 31, 2019		644,730			23.09	7.10Yrs	$	25,370

The following table has additional information regarding options exercised under both the BancFirst ISOP and the BancFirst Directors’ Stock Option Plan:

	Year Ended December 31,
	2020		2019		2018
	(Dollars in thousands)
Total intrinsic value of options exercised	$	2,315	$	3,982	$	4,810
Cash received from options exercised		1,574		2,282		2,159
Tax benefit realized from options exercised		590		1,014		1,225

The fair value of each option grant is estimated on the date of grant using the Black-Scholes option-pricing model and is based on certain assumptions including risk-free rate of return, dividend yield, stock price volatility and the expected term. The fair value of each option is expensed over its vesting period.

The following table is a summary of the Company’s recorded stock-based compensation expense:

	Year Ended December 31,
	2020		2019		2018
	(Dollars in thousands)
Stock-based compensation expense	$	1,516	$	1,277	$	1,352
Tax benefit		386		325		345
Stock-based compensation expense, net of tax	$	1,130	$	952	$	1,007

The Company will continue to amortize the unearned stock-based compensation expense over the remaining vesting period of approximately seven years. The following table shows the unearned stock-based compensation expense:

The following table shows the assumptions used for computing stock-based compensation expense under the fair value method on options granted during the periods presented:

	Year Ended December 31,
	2020			2019			2018
Weighted average grant-date fair value per share of options granted	$	10.85		$	13.34		$	14.71
Risk-free interest rate	0.64 to 1.13%			1.55 to 2.76%			2.55 to 3.05%
Dividend yield		2.00	%		2.00	%		2.00	%
Stock price volatility	22.84 to 36.10%			22.93 to 23.63%			23.05 to 23.95%
Expected term	10 Yrs			10 Yrs			10 Yrs

The risk-free interest rate is determined by reference to the spot zero-coupon rate for the U.S. Treasury security with a maturity similar to the expected term of the options. The dividend yield is the expected yield for the expected term. The stock price volatility is estimated from the recent historical volatility of the Company’s stock. The expected term is estimated from the historical option exercise experience. The Company accounts for forfeitures as they occur.

The Company has had the BancFirst Corporation Directors’ Deferred Stock Compensation Plan (the “BancFirst Deferred Stock Compensation Plan”) since May 1999. As of December 31, 2020 there are 21,943 shares available for future issuance under the BancFirst Deferred Stock Compensation Plan. The BancFirst Deferred Stock Compensation Plan will terminate on December 31, 2024, if not extended. Under the plan, directors and members of the community advisory boards of the Company and its subsidiaries may defer up to 100% of their board fees. They are credited for each deferral with a number of stock units based on the current market price of the Company’s stock, which accumulate in an account until such time as the director or community board member terminates serving as a board member. Shares of common stock of the Company are then distributed to the terminating director or community board member based upon the number of stock units accumulated in his or her account. There were 8,218 and 9,542 shares of common stock distributed from the BancFirst Deferred Stock Compensation Plan during the years ended December 31, 2020 and 2019, respectively.