A summary of shares repurchased under our stock repurchase program authorized by our Board of Directors follows:


	Three Months Ended						Nine Months Ended
	September 30,						September 30,
	2020		2019		2020		2019
Shares repurchased	—		—		2.5		1.3
Aggregate purchase price	$	—	$	—	$	80.0	$	44.7
Average purchase price per share	$	—	$	—	$	31.95	$	35.51

In October 2020, our Board of Directors increased the share repurchase authorization to $500 million.

A summary of shares of common stock issued in connection with the exercise of stock options follows:


	Three Months Ended						Nine Months Ended
	September 30,						September 30,
	2020		2019		2020		2019
Shares issued	0.6		0.1		0.7		0.2
Proceeds from the exercise of stock options	$	30.5	$	4.9	$	31.5	$	8.0
Average exercise price per share	$	48.86	$	35.61	$	46.37	$	33.70

The following table presents a summary of shares of common stock issued in connection with the settlement of RSUs, as well as shares surrendered to AutoNation to satisfy tax withholding obligations in connection with the vesting of restricted stock and settlement of RSUs:


	Three Months Ended			Nine Months Ended
	September 30,			September 30,
(In actual number of shares)	2020	2019	2020	2019
Shares issued	10,896	2,045	512,917	306,346
Shares surrendered to AutoNation to satisfy tax withholding obligations	4,288	899	190,888	85,331