# MAINSTREET RIA LLC

MAINSTREET RIA LLC of O'FALLON, MO is an SEC-registered investment adviser.

## Registration

- CRD: 309150
- Type: SEC-registered investment adviser
- SEC file number: 801-121454
- Location: 6700 KEATON CORPORATE PARKWAY, SUITE 102, O'FALLON, MO, 63368
- Phone: (888) 801-0325
- Latest filing: 2026-02-12
- Regulatory AUM: $446.4M
- Discretionary AUM: $446.4M
- Clients: 3
- Accounts: 206

## Business model

- Compensation: % of AUM, Hourly, Fixed
- Clients served: Individuals, High net worth, Pensions

## Officers, owners & control persons (6)

| Name | Role | Location |
| --- | --- | --- |
| Robert Steven Oldham | MANAGING PARTNER/INVESTMENT ADVISOR REPRESETATIVE | — |
| Richard Lee Counts | MANAGING PARTNER/INVESTMENT ADVISOR REPRESENTATIVE | — |
| Nicholas S Oldham | MANAGING PARTNER/CHIEF COMPLIANCE OFFICER/INVESTMENT ADVISOR REPRESENTATIVE | — |
| OLDHAM ROBERT STEVEN | MANAGING PARTNER/INVESTMENT ADVISOR REPRESETATIVE | — |
| COUNTS RICHARD LEE | MANAGING PARTNER/INVESTMENT ADVISOR REPRESENTATIVE | — |
| Oldham Nicholas S | CHIEF COMPLIANCE OFFICER/INVESTMENT ADVISOR REPRESENTATIVE | — |


## Related pages

- Form ADV Part 2 brochure: https://search.stillhousedata.com/firm/309150/brochure
- Similar advisers: https://search.stillhousedata.com/firm/309150/similar
- Related entities: https://search.stillhousedata.com/firm/309150/related
- SEC IAPD (source of record): https://adviserinfo.sec.gov/firm/summary/309150

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Source: public SEC Form ADV data via Adviser Search (https://search.stillhousedata.com).
Agents: this data is also queryable via MCP tools and read-only SQL — see https://search.stillhousedata.com/llms.txt.