# William Koster

> William Koster is a fee-only financial advisor at One DAY in July in Vergennes, Vermont. One DAY in July reports charging a percentage of assets and fixed fees on its Form ADV.

Page: https://find.wellspent.co/advisors/william-koster/
Built from SEC adviser records; last checked October 30, 2026.

## Facts

- **Firm:** One DAY in July
- **Based in:** Vergennes, Vermont
- **Fee model (firm's Form ADV):** Percentage of assets; Fixed fees
- **Assets under management (firm):** $1.36B across 4,011 accounts
- **CRD:** 1452809 (https://adviserinfo.sec.gov/individual/summary/1452809)
- **SEC registration:** Investment adviser representative in VT
- **Exams passed:** Series 63 (1992), Series 65 (2019)
- **Firm size:** 23 employees
- **Disclosures:** None reported
- **Website:** https://www.eventbrite.com/o/one-day-in-july-34301369503

## Frequently asked questions

### Is William Koster a fee-only financial advisor?

Yes, according to SEC records as of October 29, 2026: William holds no broker registration, and One DAY in July reports no commissions, no broker-dealer, and no insurance sales or affiliated insurance agency on its Form ADV.

### How does William charge for financial advice?

William's firm, One DAY in July, reports charging a percentage of assets and fixed fees on its SEC Form ADV.

### Where is William Koster based?

William Koster is based in Vergennes, Vermont.

### Is William Koster registered with the SEC?

Yes. William Koster is registered as an investment adviser representative in VT (CRD 1452809), per SEC Investment Adviser Public Disclosure data as of October 29, 2026.

### How much does One DAY in July manage?

One DAY in July reports $1.36B across 4,011 accounts in assets under management.

### How do I contact William Koster?

Through William's website, www.eventbrite.com/o/one-day-in-july-34301369503.

## Sources

- SEC adviser records (https://adviserinfo.sec.gov/individual/summary/1452809): the firm's Form ADV reports no commissions, no broker-dealer, and no insurance sales or affiliated insurance agency, and the advisor holds no broker registration
- SEC Investment Adviser Public Disclosure and Form ADV: registration, exams, and firm facts, data as of October 29, 2026

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Source: Wellspent, the public graph of fee-only advisors (https://find.wellspent.co). No paid placement.