William Blair & Company
BLLN

William Blair & Company’s BillionToOne Inc BLLN Stock Holding History

William Blair & Company’s Portfolio BLLN Stock Details BLLN Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2026
Q2 		$837K Buy
+6,978
New +$637K ﹤0.01% 1046

Other funds holding BLLN

ASP
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T. Rowe Price Associates
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Baillie Gifford & Co
Baillie Gifford & Co Edinburgh, United Kingdom $110B AUM 4.8% 1-Year Est. Return
Vanguard Portfolio Management
Vanguard Portfolio Management Malvern, Pennsylvania $2.22T AUM
Invesco
Invesco Atlanta, Georgia $1.26T AUM 61.52% 1-Year Est. Return
Vanguard Capital Management
Vanguard Capital Management Malvern, Pennsylvania $4.68T AUM
Neuberger Berman Group
Neuberger Berman Group New York $150B AUM 40.08% 1-Year Est. Return
BAMCO Inc
BAMCO Inc New York $66.6B AUM 7.35% 1-Year Est. Return
WA
Wasatch Advisors Salt Lake City, Utah $15.3B AUM 25.06% 1-Year Est. Return
Millennium Management
Millennium Management New York $276B AUM 44.8% 1-Year Est. Return

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

William Blair & Company opened a new position in BillionToOne Inc (BLLN) in Q2 2026: 6,978 shares worth $837K. The stake represents ﹤0.01% of the portfolio and ranks #1046 among its holdings.

157 funds tracked by Wall St. Rank hold BLLN as of Q2 2026.

  • William Blair & Company held 6,978 shares of BillionToOne Inc worth $837K as of Q2 2026.
  • BillionToOne Inc was a new William Blair & Company position in Q2 2026.
  • BillionToOne Inc made up ﹤0.01% of William Blair & Company's portfolio in Q2 2026, its #1046 holding.
  • 157 funds tracked by Wall St. Rank held BillionToOne Inc as of Q2 2026.

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