Nicholas S Oldham
Investment Adviser Representative at Mainstreet RIA LLC
Professional summary
Compiled by AdvisorFinder from public regulatory records. This advisor has not provided a personal biography.
Nicholas S. Oldham is an investment adviser representative with Mainstreet RIA LLC in O'fallon, MO, where they have been registered since 2021. They have worked in the securities industry since 2008 and have been registered with 6 firms, including Northwestern Mutual Investment Services,llc and Valic Financial Advisors, Inc. They have passed 3 industry qualification exams, including the Series 66 (combined investment adviser and state securities agent) and Series 7 (general securities representative). They are registered to provide investment advice in Missouri and Texas.
Office
Advisors at this office: 3
Branch office as filed with FINRA, counting current advisors in the directory who work there.
Registrations & licenses
- Investment adviser:
- Missouri, Texas
Registration requirements vary by state and service. Contact the advisor's firm to confirm whether they can serve you.
Financial-firm registration history
Registration history as reported to FINRA, most recent first.
Reported employment history
Employment the advisor reported on their SEC/FINRA filings, as of October 8, 2026. It may not be a complete history.
- Valic Financial AdvisorsApr 2012 – Jan 2017Saint Louis, MO
- Robert Half AccountempsJan 2017 – Jan 2018saint louis, MO
- Scott NiekampFeb 2018 – Feb 2021Chesterfield, MO
- Northwestern Mutual Investment Services LLCFeb 2018 – Feb 2021Chesterfield, MO
- Northwestern Mutual Wealth Management CompanyFeb 2018 – Feb 2021Milwaukee, WI
- Brayton KlausJan 2021 – Feb 2021Chesterfield, MO
- Mainstreet RIA LLCMar 2021 – no end date reportedO'Fallon, MO
- Sole ProprietorJan 2018 – Oct 2023O'Fallon, MO
Official records & sources
Data as of August 11, 2026 · Source: SEC IAPD & FINRA BrokerCheck
About Mainstreet RIA LLC
These details describe the firm overall. Individual advisors' services, clients, and fees may differ.
Fee arrangements the firm reports
- Percentage of assets under management
- Hourly
- Fixed fee
Arrangements the firm reports on its Form ADV; this advisor may not charge every fee listed. Estimated from the firm's Form ADV — individual terms may differ. Not a quote.
Services the firm offers
Client types the firm serves
Firm assets under management
$100M–$500M
- Firm disclosures (Form ADV)
- No disciplinary history reportedVerify on SEC IAPD
- Advisors listed on AdvisorFinder:
- 3
- Offices listed on AdvisorFinder:
- 1
- Main office:
- O'fallon, MO
- SEC file number:
- 801-121454
Counts reflect AdvisorFinder directory coverage, not necessarily the firm's complete network.
Form ADV data as of September 29, 2026
View full firm profileOther advisors at Mainstreet RIA LLC
2 other advisors in the directory
Similar advisors in O'fallon, MO
Other advisors whose filed branch office is in the same city.
This profile was compiled and published by AdvisorFinder as editorial content using publicly available information from the SEC's IAPD database and FINRA BrokerCheck. Nicholas S Oldham has not reviewed, approved, or endorsed this profile and is not responsible for its accuracy. Regulatory records change over time — always verify the current record directly on BrokerCheck or SEC.gov before making any decision. AdvisorFinder may be compensated for referrals generated through this page.
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