William Blair & Company’s Byline Bancorp BY Stock Holding History

William Blair & Company’s Portfolio BY Stock Details BY Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2026 Q2	$3.01M	Buy	79,924 +3,938	+5%	+$132K	0.01%	654
2026 Q1	$2.4M	Sell	75,986 -6,953	-8%	-$218K	0.01%	679
2025 Q4	$2.42M	Buy	82,939 +3,815	+5%	+$107K	0.01%	697
2025 Q3	$2.19M	Buy	79,124 +71,401	+925%	+$1.99M	0.01%	710
2025 Q2	$206K	Buy	+7,723	New	+$198K	﹤0.01%	1413
2021 Q4	–	Sell	-16,200	Closed	-$398K	–	1974
2021 Q3	$398K	Sell	16,200 -7,826	-33%	-$187K	﹤0.01%	1246
2021 Q2	$544K	Buy	24,026 +9,025	+60%	+$202K	﹤0.01%	1125
2021 Q1	$317K	Sell	15,001 -3,889	-21%	-$72.9K	﹤0.01%	1305
2020 Q4	$292K	Buy	18,890 +3,890	+26%	+$56.6K	﹤0.01%	1280
2020 Q3	$169K	Hold	15,000	–	–	﹤0.01%	1346
2020 Q2	$197K	Sell	15,000 -5,000	-25%	-$57.2K	﹤0.01%	1248
2020 Q1	$207K	Hold	20,000	–	–	﹤0.01%	1155
2019 Q4	$391K	Sell	20,000 -25,176	-56%	-$460K	﹤0.01%	1084
2019 Q3	$808K	Sell	45,176 -22,813	-34%	-$413K	﹤0.01%	811
2019 Q2	$1.3M	Buy	67,989 +47,989	+240%	+$920K	0.01%	695
2019 Q1	$370K	Hold	20,000	–	–	﹤0.01%	1066
2018 Q4	$333K	Hold	20,000	–	–	﹤0.01%	1050
2018 Q3	$454K	Hold	20,000	–	–	﹤0.01%	989
2018 Q2	$447K	Hold	20,000	–	–	﹤0.01%	983
2018 Q1	$459K	Hold	20,000	–	–	﹤0.01%	949
2017 Q4	$459K	Hold	20,000	–	–	﹤0.01%	993
2017 Q3	$425K	Hold	20,000	–	–	﹤0.01%	988
2017 Q2	$401K	Buy	+20,000	New	+$401K	﹤0.01%	1057

Other funds holding BY

BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return

Dimensional Fund Advisors Austin, Texas $552B AUM 44.19% 1-Year Est. Return

T. Rowe Price Investment Management Baltimore, Maryland $153B AUM 38.14% 1-Year Est. Return

Vanguard Capital Management Malvern, Pennsylvania $4.68T AUM

State Street Boston, Massachusetts $3.37T AUM 44.26% 1-Year Est. Return

American Century Companies Kansas City, Missouri $226B AUM 44.75% 1-Year Est. Return

Boston Partners Boston, Massachusetts $113B AUM 38.87% 1-Year Est. Return

Federated Hermes Pittsburgh, Pennsylvania $69.6B AUM 42.52% 1-Year Est. Return

AQR Capital Management Greenwich, Connecticut $287B AUM 42.33% 1-Year Est. Return

Geode Capital Management Boston, Massachusetts $1.88T AUM 44.46% 1-Year Est. Return

William Blair & Company's BY Position: Q2 2026 in Review

William Blair & Company increased its Byline Bancorp (BY) stake by 5.2% in Q2 2026, buying an estimated $132K and bringing the position to 79,924 shares worth $3.01M. The position accounts for 0.01% of the portfolio, ranked #654.

William Blair & Company first reported a position in BY in Q2 2017 and has held it in 23 quarters since. 207 funds tracked by Wall St. Rank hold BY as of Q2 2026.

William Blair & Company held 79,924 shares of Byline Bancorp worth $3.01M as of Q2 2026.
William Blair & Company bought 3,938 Byline Bancorp shares in Q2 2026, an estimated $132K.
Byline Bancorp made up 0.01% of William Blair & Company's portfolio in Q2 2026, its #654 holding.
William Blair & Company first reported a position in Byline Bancorp in Q2 2017 and has held it in 23 quarters since.
207 funds tracked by Wall St. Rank held Byline Bancorp as of Q2 2026.

Based on William Blair & Company's 13F filing for Q2 2026, filed 11 Aug 2026.