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Duncker Streett & Co.
Charles Duncker and Donald Streett spun their St. Louis Brown Brothers Harriman branch into RIA Duncker Streett & Co.
Duncker Streett & Co.
Duncker Streett & Co. was founded in 1990 when Charles Duncker and Donald Streett — both veterans of Brown Brothers Harriman's St. Louis trust office — purchased the local branch outright. The founders have since departed, leaving a generational firm that serves a client base stretching back as far as four decades. The practice operates as a Registered Investment Advisor, legally bound to a fiduciary standard that places client interests above firm interests. Investment management runs on a case-by-case mandate. The firm constructs portfolios primarily from individual equities and fixed-income securities, forgoing model portfolios in favor of direct security selection tailored to each client's distinct tax, income and legacy circumstances. Client types span individuals, trusts, pension and profit-sharing plans, endowments, charitable trusts, corporations and personal-holding companies. While the firm's St. Louis roots anchor it firmly in the Midwest, its fiduciary model and individual-security approach appeal to institutional relationships nationwide. Principals bring more than 60 years of combined investment experience, holding advanced designations that attest to specialized training. Duncker Streett operates from a single office at 8000 Maryland Avenue in Clayton, Missouri. The firm's longevity — serving wealth across four generations — reflects a client-retention dynamic built on personalized service rather than transactional brokerage. Structurally, Duncker Streett is distinguished by its origin as a carve-out from a private-bank trust department. That lineage embeds a trustee's sensibility — steady, liability-aware and oriented toward permanent capital — inside an RIA wrapper. The firm's bias toward individual securities over funds cements a control-and-customization promise that few fiduciary shops of comparable size still deliver.
General information
Firm type
Bank / Wealth / Trust
Year founded
1990
AUM
Undisclosed
Location
Region
North America
Country
United States
City
St. Louis
Corporate office
8000 Maryland Avenue, Suite 1100, St. Louis, MO 63105, United States
Principals
Charles Duncker
Co-Founder
Donald Streett
Co-Founder
Sector focus
Frequently asked questions
How is Duncker Streett & Co. structured — is it a family office or an asset manager?
Duncker Streett & Co. is a Registered Investment Advisor, not a single-family office. It manages assets for a mix of individuals, trusts, pension plans, endowments, charitable trusts, corporations and personal-holding companies. The firm operates under a fiduciary mandate, which legally requires it to place client interests ahead of its own.
Who makes investment decisions at Duncker Streett & Co.?
The firm's principals — who collectively carry more than 60 years of investment experience — manage portfolios directly. They invest primarily in individual equities and fixed-income securities chosen to reflect each client's distinct financial goals. No separate investment committee or external sub-advisor is disclosed.
What is Duncker Streett & Co.'s investment approach?
The firm builds custom portfolios using individual stocks and bonds rather than model portfolios, mutual funds or ETFs. Each account is managed case-by-case, with security selection driven by the client's tax situation, income needs and legacy objectives. The firm manages equity and fixed-income allocations in-house.
Does Duncker Streett & Co. invest in private equity, venture capital or alternatives?
No mandate for private equity, venture capital or alternative assets is disclosed. The firm states that it invests "primarily in individual securities," suggesting a core public-markets equity and fixed-income focus. No fund-of-funds or private-market vehicles are mentioned.
Where does Duncker Streett & Co. source clients, and what is its geographic reach?
The firm is headquartered in Clayton, Missouri, and its deep roots in the St. Louis community date to the 1960s, when its founders worked at Brown Brothers Harriman's local trust office. While its institutional and individual client base likely extends nationally, all operations run from the single Maryland Avenue office.
How does Duncker Streett & Co.'s fiduciary structure affect client portfolios?
As a Registered Investment Advisor, the firm is ethically and legally obligated to act in each client's best interests. This fiduciary standard governs every recommendation and trade, distinguishing it from broker-dealer models. The firm's ADV disclosures are publicly available for review.
What is Duncker Streett & Co.'s relationship with Brown Brothers Harriman?
The firm traces its origin directly to Brown Brothers Harriman's St. Louis trust branch, where founders Charles Duncker and Donald Streett worked starting in the 1960s. In 1990, the two purchased the local branch and formed Duncker Streett & Co. as an independent RIA. No ongoing ownership or business relationship with Brown Brothers Harriman is disclosed.
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