Who We Are

  • George Gumbiner


    George, a native of Denver, received a BA and an MA in public administration from the University of Colorado in Boulder. He has also studied at the Hebrew University of Jerusalem, 1973-1974.


    Since graduation, Gumbiner has been in the employ of Bank Leumi le Israel, Omnibancorp and MDC Holdings, along with three major investment companies, E.F. Hutton, Prudential Securities and A.G. Edwards & Sons, Inc., the latter for over nine years.


    He is also involved in numerous non-profit and charitable organizations both here in Colorado and globally.

  • Stephanie K Ruark


    Stephanie is our newest team member to Marathon Investments. She brings with her 20 years of knowledge and experience in the retirement planning, investment and insurance arena; from 401(k)’s, 403(b)’s, SIMPLE IRA’s, college saving plans, to trust accounts and managed investment accounts, as well as life insurance and annuity planning.

    Stephanie is a native to Colorado and loves to spend time outdoors camping, skiing and hiking with her husband and their blended family of a daughter and four sons.

  • Bolet Duman

    Financial Advisor 

    Bolet moved to CO from NJ where he received his BA in Financial Planning from William Paterson University. He previously worked for PNC Bank who sponsored him for his Series 7 (Securities License) and he is currently working towards the CFP designation.


    Bolet’s primary responsibilities include developing and implementing personal financial plans, reviewing investments, presenting educational and retirement workshops, creating hypothetical reports for clients, and continuing to assist our clients achieve their financial goals.


    Bolet enjoys snowboarding, practicing kickboxing and Jui Jitsu as well as spending time with his cousins in CO hiking and camping.


  • Genesis Fox

    Administrative Assistant

    Genesis comes to us with five years’ experience providing consistent approachable customer service for customers and vendors at Dish Network and other companies. She is very personable and has high standards of excellence in her work ethic. Genesis also displays outstanding communication skills, continuously projecting a highly professional image while adapting quickly to new and evolving changes within the industry.


    Genesis Fox was born in Jacksonville, Florida but has lived most of her life in Colorado. She loves going to the movies, playing PlayStation 4 and most importantly spending time with her dog Tux.