Portolan Capital Invests $4.17M in Custom Truck One Source

Hedge fund buys 649,076 shares of specialty equipment rental company

Mar. 14, 2026 at 9:40am

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Portolan Capital Management LLC purchased a new position in shares of Custom Truck One Source, Inc. (NYSE:CTOS) during the third quarter, acquiring 649,076 shares valued at approximately $4,167,000. The move comes as other institutional investors, including Boston Partners, Dimensional Fund Advisors, and Allspring Global Investments, have also increased their stakes in the specialty equipment rental company.

Why it matters

Custom Truck One Source has seen increased institutional investment interest as the company expands its fleet and branch network across North America to serve customers in construction, energy, telecommunications, and other industries. The influx of capital could support the company's growth initiatives.

The details

Portolan Capital Management, a Boston-based hedge fund, added the Custom Truck One Source position in the third quarter. The company provides a wide range of specialty rental equipment, parts, and services, with a focus on cranes, aerial work platforms, trench safety, fluid management solutions, and other industrial machinery. Custom Truck One Source has grown both organically and through strategic acquisitions, now operating more than 140 branch locations across the U.S. and Canada.

  • Portolan Capital purchased the new position in Custom Truck One Source during the third quarter of 2026.
  • Other institutional investors, including Boston Partners, Dimensional Fund Advisors, and Allspring Global Investments, have also increased their stakes in Custom Truck One Source in recent quarters.

The players

Portolan Capital Management LLC

A Boston-based hedge fund that purchased a new position in shares of Custom Truck One Source, Inc.

Custom Truck One Source, Inc.

A North American provider of specialty rental equipment, parts, and services, with a focus on cranes, aerial work platforms, trench safety, fluid management solutions, and other industrial machinery.

Boston Partners

An institutional investor that increased its stake in Custom Truck One Source by 0.8% in the third quarter.

Dimensional Fund Advisors LP

An institutional investor that increased its stake in Custom Truck One Source by 8.3% in the third quarter.

Allspring Global Investments Holdings LLC

An institutional investor that increased its stake in Custom Truck One Source by 2.2% in the third quarter.

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