William Blair Small-Mid Cap Growth Fund

Bottom-up U.S. small- and mid-cap growth investing in high-quality companies expected to sustain above-market growth for longer than investors anticipate.$1.2B AUM6 published ideas

William Blair Small-Mid Cap Growth Fund invests in high-quality U.S. small- and mid-cap companies that the manager believes can sustain a higher level of growth for longer than the market expects. The strategy relies on bottom-up fundamental research and seeks durable franchises with strong management, barriers to entry and differentiated offerings.

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Ideas from William Blair Small-Mid Cap Growth Fund

LongTWSTJun 2026

Twist Bioscience Corp.

Twist Bioscience's competitive moat comes from miniaturizing DNA manufacturing on silicon, enabling far greater scale than legacy methods. The company is delivering broad…

LongONTOJun 2026

Onto Innovation

Onto Innovation provides process-control solutions across semiconductor inspection, metrology and lithography. Strong quarterly results and higher 2026 revenue guidance were…

LongSTRLJun 2026

Sterling Infrastructure

Sterling Infrastructure has transformed from a regional civil contractor into an infrastructure provider tied to the AI buildout. Its E-Infrastructure segment, which serves data…

LongBSYJun 2026

Bentley Systems

Bentley Systems provides engineering software for end-to-end infrastructure construction and delivered a broad-based quarterly beat while maintaining guidance. Demand from…

LongBWXTJun 2026

BWX Technologies

BWX Technologies supplies complex nuclear components and services to U.S. naval nuclear propulsion, national security and growing commercial nuclear applications. The underlying…

LongCCJJun 2026

Cameco

Cameco is exposed to the uranium supply chain as nuclear energy gains recognition as reliable, carbon-free baseload power for AI data centers. The company reported solid…

Letters covered

  • Small-Mid Cap Growth Fund Quarterly ReviewJune 30, 2026

Source PDFs are not republished here; only extracted ideas and quotes.