William Blair & Company
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William Blair & Company’s Amprius Technologies AMPX Stock Holding History

William Blair & Company’s Portfolio AMPX Stock Details AMPX Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2026
Q1 		$2.13M Buy
126,622
+86,470
+215% +$1.13M 0.01% 719
2025
Q4 		$317K Buy
40,152
+15,364
+62% +$176K ﹤0.01% 1288
2025
Q3 		$261K Buy
+24,788
New +$195K ﹤0.01% 1355

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BlackRock
BlackRock New York $5.72T AUM 30.48% 1-Year Est. Return
VCM
Vanguard Capital Management Malvern, Pennsylvania $4.04T AUM
Jane Street
Jane Street New York $777B AUM 61.18% 1-Year Est. Return
DCM
Driehaus Capital Management Chicago, Illinois $13.6B AUM 173.98% 1-Year Est. Return
Two Sigma Investments
Two Sigma Investments New York $124B AUM 33.93% 1-Year Est. Return
Morgan Stanley
Morgan Stanley New York $1.66T AUM 25.57% 1-Year Est. Return
Geode Capital Management
Geode Capital Management Boston, Massachusetts $1.61T AUM 30.72% 1-Year Est. Return
State Street
State Street Boston, Massachusetts $2.9T AUM 29.55% 1-Year Est. Return
UBS Group
UBS Group Zurich, Switzerland $666B AUM 30.12% 1-Year Est. Return
Goldman Sachs
Goldman Sachs New York $871B AUM 31.28% 1-Year Est. Return

William Blair & Company's AMPX Position: Q1 2026 in Review

William Blair & Company increased its Amprius Technologies (AMPX) stake by 215% in Q1 2026, buying an estimated $1.13M and bringing the position to 126,622 shares worth $2.13M. The position accounts for 0.01% of the portfolio, ranked #719.

William Blair & Company first reported a position in AMPX in Q3 2025 and has held it in 3 quarters since. 245 funds tracked by Wall St. Rank hold AMPX as of Q1 2026.

  • William Blair & Company held 126,622 shares of Amprius Technologies worth $2.13M as of Q1 2026.
  • William Blair & Company bought 86,470 Amprius Technologies shares in Q1 2026, an estimated $1.13M.
  • Amprius Technologies made up 0.01% of William Blair & Company's portfolio in Q1 2026, its #719 holding.
  • William Blair & Company first reported a position in Amprius Technologies in Q3 2025 and has held it in 3 quarters since.
  • 245 funds tracked by Wall St. Rank held Amprius Technologies as of Q1 2026.

Based on William Blair & Company's 13F filing for Q1 2026, filed 8 May 2026.