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Investment Strategies Based On Experience

About Us

About Us

Oatley & Diak, LLC is a family-run registered investment advisory (RIA) firm that provides clients with investment management and financial planning services in a hands-on, intimate environment. Our diverse wealth of education and industry experience gives you access to a reservoir of knowledge to assess and construct a strategy that can identify your unique needs. We offer a process-driven, value approach to create a financial plan that will assist in achieving results over the long term. The investments utilized in this approach adhere to our strict set of requirements. Each client’s goals and objectives are reviewed using a disciplined monitoring process with one-on-one client meetings.

Our team environment transcends the firm structure. We work with your other advisors, such as CPAs and attorneys, to create a streamlined approach to managing your wealth.

John Diak

John J. Diak, CFP®

John J. Diak, CFP
John J Diak, CFP Client Wealth Manager

Principal & Client Wealth Manager

Community/Civic Affiliations

  • Colorado Department of Transportation (CDOT) – Liaison

  • Denver Regional Council of Governments (DRCOG) – Board Member

  • Parker Authority For Reinvestment (PAR) – Board Member

  • Parker Chamber of Commerce - Member

  • Regional Transportation District (RTD) - Liaison

  • Rotary International – Cherry Creek Valley Club

  • Southeast Christian Church – Financial Coaching Ministry

  • Town of Parker – Councilmember

  • Town of Parker Economic Development Committee – Liaison

John’s interest in the financial services industry can be traced back to his college days when he earned bachelor's degrees in both finance and human development and family studies, followed by a master's degree in finance. He wanted to understand the key aspects of the financial lifecycle and integrate financial discipline to assist individuals in successfully planning for those events.

As a CERTIFIED FINANCIAL PLANNER™, John assists clients through many difficult lifestyle changes, such as business downturns, retirement planning, divorce, the death of a spouse, and family estate issues, among others. Clients benefit from his experience in both the business and the financial academic world. John’s attention to detail and straightforward, hands-on approach to issues have consistently produced results for clients. His focus is to provide all clients with superior service by understanding their needs and providing relevant information in an easy-to-understand format.


John was featured in the book Relax in Retirement: Conversations with Denver Professionals on Maximizing Your Sunset Years as a professional who shared insights and expertise on financial planning and preparing for retirement.


John is involved in various community activities and organizations, including the Cherry Creek Valley Rotary Club, Financial Coaching Ministry at Southeast Christian Church, E-470 Safety Foundation, and the Stay Alive on Highway 83 program. In addition, he has donated professional services to local organizations, including Praying Hands Ranch, Parker Senior Center, Double Angel Ballpark, and the Miller Safety Center.


In November 2012, John was elected to the Parker Town Council. He continues in this role today, lending his strong financial background and diverse land use knowledge to ensure Parker remains a vibrant and evolving community.


John and his wife Noelle live in Parker, Colorado, with their three children – Justin, Tyler, and Mikaya. In his free time, John enjoys spending time with his family, golfing, and running.


  • MSF, Master of Science – Finance, University of Colorado – Denver

  • BS, Business Administration – Finance, Colorado State University

  • BS, Human Development and Family Studies, Colorado State University

Professional Affiliations

  • Colorado Collaborative Divorce Professionals
  • Financial Planning Association
  • Institute For Divorce Financial Analysts
  • International Academy of Collaborative Professionals
  • International Council of Shopping Centers



  • CDFA®, Certified Divorce Financial Analyst®


  • Denver Five Star Professional

Noelle entered the financial services industry with Janus Funds, a Denver-based mutual fund company, where she assisted her portfolio of clients with their unique, comprehensive financial needs. Noelle provided service center assistance to a broad range of clients. The experience at Janus Funds allowed Noelle to discover her passion: working with her clients on a more personal level.


In 2002, Noelle left Janus Funds to establish Oatley & Diak, LLC with her father, Don Oatley. The vision of Oatley & Diak, LLC was (and still is) to offer a more personal, intimate approach to investing. She has created a culture where the client is first, spending time with each client and listening. Once Noelle understands the client’s unique situation, they are provided with a customized plan tailored to their specific needs. 


Noelle’s hallmark is her focus on providing prompt and courteous service, which endears her to clients. Her dedication and ability to relate to clients have resulted in many personal friendships.


In addition to providing wealth advisory services, Noelle focuses on the compliance, reporting, and information technology (IT) aspects of the firm. Noelle’s continuing development of technology allows the firm to implement and rely on cutting-edge tools to service clients.


Noelle enjoys spending time with her husband and their three children, friends and family, as well as traveling and reading whenever possible. 

Noelle O. Diak

Client Wealth Manager

Noelle O. Diak, Client Wealth Manager
Noelle Diak


  • BS, Merchandising, Colorado State University

  • Personal Financial Planning Certificate, Metropolitan State University of Denver

Professional Affiliations

  • Colorado Women’s Chamber of Commerce

  • Financial Planning Association

Community/Civic Affiliations

  • Kappa Alpha Theta  Alumnae Board – Past Treasurer

  • American Academy – Uniform Committee

  • Southeast Christian Church – Vacation Bible School (VBS) Teacher

  • Southeast Christian Church – Choir Member

  • Girl Scouts of America –Troop Leader

Donald F. Oatley, CPA, PFS

Donald Oatley
Donald F. Oatley, CPA, PFS, Business & Investment Consultant Don Oatley

Business & Investment Consultant

Don moved full-time into investment advising after selling his mid-size CPA firm in 2001. With over three decades of experience as a certified public accountant and fifteen years of experience in the financial services industry, Don’s experience as both a trusted CPA and financial advisor positions him to help clients chart a sustained and profitable course of secure investing.


As a CPA, Don assisted clients through many difficult lifecycle challenges such as business downturns, divorce, family estate issues, the death of a spouse, and retirement issues, among others, so he understands the relationship between investing and financial security. Don’s philosophy of “Value Investing” (buying quality investments at discounted prices) has helped grow his clients’ assets while minimizing their risks.


Don has been active in the Colorado Society of CPAs (CSCPA) as a member of the board of directors and as vice president. He is a member of the financial planning committee and has helped implement personal financial planning and investment conferences sponsored by the CSCPA.


Don served in the U.S. Navy as a Naval Flight Officer, saw service in Vietnam, and retired from the Naval Reserve with the rank of Captain. When not engaged in his passion (investing his and his clients’ money), Don enjoys spending time with his three grandchildren, fly fishing, hiking, trap shooting, and traveling.


  • MBA, University of Denver

  • MT, Masters in Taxation, University of Denver

  • BA, Zoology, University of Hawaii



  • CPA, Certified Public Accountant

  • PFS, Personal Financial Specialist


Professional Affiliations

  • American Institute of Certified Public Accountants

  • Colorado Society of Certified Public Accountants

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