STOCK-BASED COMPENSATION (Tables)

9 Months Ended

Sep. 30, 2023

Share-Based Payment Arrangement [Abstract]

Stock-based compensation expense

Stock-based compensation expense (benefit) was as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2023		2022		2023		2022
	($ in millions)
Stock-based compensation	$	6.7	$	5.8	$	19.5	$	20.0
Mark-to-market adjustments	(2.3)		(2.0)		(2.4)		(10.5)
Total expense	$	4.4	$	3.8	$	17.1	$	9.5

Schedule of fair value of stock options granted valuation assumptions

The fair value of each stock option granted, which typically vests ratably over three years, but not less than one year, was estimated on the date of grant, using the Black-Scholes option-pricing model with the following weighted-average assumptions:

Grant date	2023			2022
Dividend yield	1.32		%	1.60		%
Risk-free interest rate	4.07		%	1.93		%
Expected volatility of Olin common stock	47		%	48		%
Expected life (years)	7.0			7.0
Weighted-average grant fair value (per option)	$	28.74		$	21.18
Weighted-average exercise price	$	60.55		$	49.71
Options granted	562,124			742,100

Schedule of fair value of performance share awards granted valuation assumptions

The fair value of each performance share award based on TSR was estimated on the date of grant, using a Monte Carlo simulation model with the following weighted average assumptions:

Grant date	2023			2022
Risk-free interest rate	4.46		%	1.74		%
Expected volatility of Olin common stock	52		%	59		%
Expected average volatility of peer companies	42		%	47		%
Average correlation coefficient of peer companies	0.51			0.51
Expected life (years)	3.0			3.0
Grant date fair value (TSR based award)	$	86.98		$	64.13
Grant date fair value (net income based award)	$	60.55		$	49.71
Awards granted	161,474			184,000