Stock-based compensation granted includes stock options, performance share awards, restricted stock awards and deferred directors’ compensation. Stock-based compensation expense was as follows:


	Three Months Ended June 30,				Six Months Ended June 30,
	2026		2025		2026		2025
Stock Compensation Expense	($ in millions)
Stock-based compensation	$	9.7	$	9.2	$	16.9	$	14.5
Mark-to-market adjustments	(5.4)		(1.9)		(1.1)		(5.7)
Total expense	$	4.3	$	7.3	$	15.8	$	8.8

Performance share awards are denominated in shares of Olin’s stock and are paid half in cash and half in stock. All performance share awards vest ratably and are paid out at the end of the three-year performance period, contingent upon the achievement of specified performance conditions.

Performance share awards granted during 2026 will have a payout between 0% and 240% based on Olin’s earnings over the three-year performance cycle, in relation to the earnings targets for such period set by the Compensation Committee of Olin’s Board of Directors, including a performance multiplier for Olin’s Total Shareholder Return (TSR) over the applicable three-year performance cycle in relation to the TSR over the same period among a portfolio of public companies which are selected in concert with outside compensation consultants.

Performance share awards granted before 2026 will have a payout between 0% and 200% based on two criteria: (1) 50% of the award is based on Olin’s TSR over the applicable three-year performance cycle in relation to the TSR over the same period among a portfolio of public companies which are selected in concert with outside compensation consultants and (2) 50% of the award is based on Olin’s net income over the applicable three-year performance cycle in relation to the net income goal for such period as set by the Compensation Committee.

The fair value of each performance share award based on a performance condition was estimated on the date of grant, using the current stock price. The fair value of each performance share award based on a market condition, or TSR, was estimated on the date of grant using a Monte Carlo simulation model. Compensation cost associated with performance share awards is recognized ratably over the service period.

During the six months ended June 30, 2026 and 2025, Olin granted performance share awards of 665,432 and 573,479, respectively, at a weighted average grant date fair value per share of $25.80 and $27.46, respectively, or 103% and 99% of the grant date share price, respectively.

During the six months ended June 30, 2026 and 2025, Olin granted restricted stock units of 488,807 and 452,863, respectively, at a weighted average grant date fair value per share of $24.97 and $26.96, respectively. The fair value of each restricted stock unit was estimated on the date of grant using the current stock price. The awards typically vest ratably, on an annual basis, over three years, but not less than one year.