Gilder Gagnon Howe & Co’s Summit Materials, Inc. Class A Common Stock SUM Stock Holding History

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2018 Q3	–	Sell	-351,439	Closed	-$9.07M	–	299
2018 Q2	$9.07M	Sell	351,439 -118,252	-25%	-$3.29M	0.1%	135
2018 Q1	$14M	Buy	469,691 +16,247	+4%	+$501K	0.17%	107
2017 Q4	$14M	Sell	453,444 -13,642	-3%	-$411K	0.19%	100
2017 Q3	$14.5M	Sell	467,086 -4,739	-1%	-$134K	0.2%	94
2017 Q2	$13.2M	Buy	471,825 +118,015	+33%	+$3.07M	0.2%	100
2017 Q1	$8.48M	Buy	353,810 +44,423	+14%	+$1.04M	0.14%	108
2016 Q4	$7.14M	Sell	309,387 -2,966	-0.9%	-$62.2K	0.14%	108
2016 Q3	$5.55M	Sell	312,353 -28,692	-8%	-$555K	0.1%	119
2016 Q2	$6.69M	Sell	341,045 -10,749	-3%	-$215K	0.13%	95
2016 Q1	$6.56M	Buy	351,794 +48,291	+16%	+$790K	0.13%	99
2015 Q4	$5.83M	Sell	303,503 -22,260	-7%	-$454K	0.09%	112
2015 Q3	$5.77M	Buy	325,763 +180,410	+124%	+$4.15M	0.09%	124
2015 Q2	$3.5M	Buy	145,353 +71,411	+97%	+$1.7M	0.05%	168
2015 Q1	$1.55M	Buy	+73,942	New	+$1.5M	0.02%	191