We grant RSUs, and prior to January 2020 we granted RSAs, to participants in our equity plans. Performance-based RSUs granted in the six months ended June 29, 2024 included certain grants that vest based on our total shareholder return ranking relative to the Nasdaq US Benchmark Auto Parts Index over a three-year performance period (market condition), and other grants that vest based upon achievement of return on invested capital targets over a three-year performance period (performance condition).

Compensation cost related to RSA and RSU grants was $3.2 million and $2.6 million for the three months ended June 29, 2024 and July 1, 2023, respectively, and $5.7 million and $4.3 million for the six months ended June 29, 2024 and July 1, 2023 respectively, and was included in selling, general and administrative expenses in the Condensed Consolidated Statements of Operations.


	Shares	Weighted Average Fair Value
Balance at December 31, 2023	257,554	$	97.33
Granted	184,007	$	98.95
Vested	(55,401)	$	88.63
Canceled	(27,523)	$	112.99
Balance at June 29, 2024	358,637	$	98.30

For the six months ended June 29, 2024, we granted 32,109 performance-based RSUs containing a market condition with a grant date fair value of $138.58 per share. For the six months ended July 1, 2023, we granted 29,399 performance-based RSUs containing a market condition with a grant date fair value of $113.15 per share.

As of June 29, 2024, there was $24.8 million of unrecognized compensation cost related to unvested RSA and RSU grants that is expected to be recognized over a weighted average period of 2.3 years.

From time to time, we grant stock options to participants in our equity plans. Compensation cost related to stock option grants was $0.4 million and $0.6 million for the three months ended June 29, 2024 and July 1, 2023, respectively, and $0.8 million and $1.0 million for the six months ended June 29, 2024 and July 1, 2023, respectively, and was included as selling, general and administrative expenses in the Condensed Consolidated Statements of Operations.

The following table summarizes our stock option activity for the six months ended June 29, 2024:


	Shares	Weighted Average Price		Weighted Average Remaining Term (years)	Aggregate Intrinsic Value (in thousands)
Balance at December 31, 2023	311,217	$	86.52

Canceled	(6,416)	$	94.50
Exercised	(10,311)	$	63.73
Balance at June 29, 2024	294,490	$	87.14	4.9	$	2,192
Exercisable at June 29, 2024	192,637	$	83.34	4.3	$	2,160

As of June 29, 2024, there was $2.9 million of unrecognized compensation cost related to unvested stock options that is expected to be recognized over a weighted average period of 2.2 years.

During the three and six months ended June 29, 2024, we issued 13,555 shares under the ESPP. During the three and six months ended July 1, 2023, we issued 14,975 shares under the ESPP.