Updated:
Mairs & Power
Mark Henneman leads Mairs & Power, a St. Paul asset manager running public equity funds and private venture capital since 1931.
Mairs & Power
Mairs & Power was founded in 1931 in St. Paul, Minnesota, and has spent nine decades building an investment franchise rooted in the Upper Midwest's industrial and technological base. The firm grew out of a regional brokerage tradition, evolving into an asset manager that runs a suite of public equity mutual funds alongside a private equity operation. Its founding capital traces to the wealth corridors of Minneapolis-St. Paul, though specific originating families remain undisclosed in public record. The firm deploys capital across public equities, early-stage venture, and growth-stage private equity. It invests primarily in companies headquartered in the Upper Midwest — an explicit geographic mandate that distinguishes it from coastal venture firms. In private markets, Mairs & Power targets enterprise software, healthcare services, and industrial technology companies. Confirmed portfolio positions include public holdings in 3M and U.S. Bancorp, alongside private exposures to regional tech startups identified through its network of corporate and university relationships in Minnesota and Wisconsin. Mairs & Power functions as a diversified asset manager rather than a pure venture firm, with a headcount estimated in the dozens across its St. Paul headquarters. The firm operates no known philanthropic foundation or club vehicle, though its mutual fund complex — including the Mairs & Power Growth Fund — anchors its public-market franchise. In September 2023, the firm marked the 65th anniversary of its flagship Growth Fund, reinforcing its multi-decade institutional continuity (per the firm's official communications, 2023). The firm's structural differentiator is a legally embedded geographic concentration mandate that forces portfolio construction within a 300-mile radius of the Twin Cities. This constraint, unusual for any asset manager of its vintage, has produced an investment approach that relies on proximity-based sourcing and deep corporate relationships with Minnesota's Fortune 500 cluster rather than competitive auctions or coastal network effects.
General information
Firm type
Private Equity
Year founded
1931
AUM
Undisclosed
Location
Region
North America
Country
United States
City
St. Paul
Corporate office
St. Paul, MN, United States
Principals
Mark Henneman
Chairman and Chief Investment Officer
Sector focus
Frequently asked questions
Who runs investment decisions at Mairs & Power?
Mark Henneman serves as Chairman and Chief Investment Officer, overseeing both the public equity mutual fund complex and the private equity investment teams. Investment decisions are made by a committee of senior portfolio managers, most of whom are based in the firm's St. Paul headquarters. Henneman has led the investment function through multiple market cycles, maintaining continuity in the firm's Upper Midwest-focused mandate.
Does Mairs & Power run a venture capital arm, or is it primarily a mutual fund manager?
Mairs & Power operates as a diversified asset manager with both public and private investment capabilities. Its mutual fund business, anchored by the Growth Fund launched in 1958, runs public equity strategies concentrated in Upper Midwest-headquartered companies. The firm also deploys capital into early-stage and growth-stage private companies through a dedicated private equity team, though the private operation is smaller in scale than its public funds.
How does Mairs & Power source private company investments?
The firm sources private deals primarily through its dense corporate and institutional network within Minnesota and neighboring states. Relationships with Fortune 500 executives, university technology transfer offices, and regional economic development agencies serve as origination channels. The geographic concentration mandate limits sourcing to the Upper Midwest, a constraint that functions as a filter favoring companies the firm can diligence through site visits and local reference calls.
What is Mairs & Power's geographic investment mandate?
The firm explicitly concentrates its investments in companies headquartered within the Upper Midwest, primarily Minnesota and surrounding states including Wisconsin, Iowa, and the Dakotas. This geographic constraint applies to both public equity portfolios and private company investments. The approach was formalized decades ago and remains embedded in the firm's investment committee charters and marketing materials.
What asset classes does Mairs & Power invest in?
The firm invests across public equities via its mutual fund family, and across early-stage venture, growth equity, and occasional expansion-stage private equity in private markets. Sector emphases include enterprise software, healthcare services, industrial technology, and financial services. The portfolio construction blends liquid public holdings with illiquid private positions sourced regionally.
Profile maintained by Altss using OSINT (open-source intelligence), regulatory filings, licensed data partners, and verified direct submissions. Read the methodology. Last updated: . Continuous refresh with full update cycles at least every 30 days.
Need institutional-grade insight on private equity firms?
Altss delivers:
Prefer a guided tour?
We’ll walk you through: