Our Team

Neptune Beach, Florida

DEM Team Neptune Beach, FL
Don Davey

Senior Portfolio Manager

Senior Portfolio Manager Don Davey is the first and only four-time First Team Academic All-American in NCAA history. After graduating with honors with both Bachelor’s and Master’s Degrees in Mechanical Engineering from the University of Wisconsin, Don went on to play for nine seasons in the NFL with the Green Bay Packers and Jacksonville Jaguars. During his NFL career, he relied upon his extensive background in statistics to develop the firm’s philosophy of Portfolio Engineering. Don launched DEM in July of 1998 in response to requests from investors seeking a systematic approach to investing. Don and his wife Kristen live in Atlantic Beach, Florida, and have five daughters Livy, Carly, Kuki, Chloe, and Kasey. He is an avid triathlete and has completed 13 IRONMAN® distance triathlons.
Sarah Callaway

Chief Financial Officer

Sarah Callaway serves as DEM’s Chief Financial Officer. She has a Business Finance degree as well as an MBA from the University of Phoenix. Before joining the DEM team, she proudly served the United States Navy as a Sonar Technician as well as worked two years at the New York Times winning the coveted Star Award. She lives in Jacksonville with her husband, daughter, and chocolate lab, Blueberry. On the weekends, she enjoys going to the beach, playing with her daughter in the park, and Sudoku puzzles.

Jessica Shores

Lead Accountant

Jessica Shores is Lead Accountant at DEM. She served in the US Navy for 24 years as a Hospital Corpsman and retired as a Senior Chief. She currently lives in Jacksonville with her two children. She enjoys traveling, reading, and enjoying Florida weather.

Gabbie Herman

Chief Operating Officer

Gabbie Herman joined the DEM Team in 2024 to serve as the Operation and Compliance Manager and is now Chief Operating Officer. She has a Bachelor of Arts degree in Sociology from the University of Mississippi (Hotty Toddy!). Her professional background includes administration, entrepreneurship, and consultation. After living abroad for several years, she came back to the US and started working as the Administrative Assistant at FSA Investment Group in Pensacola, FL. While there, she discovered her love of investments and passion for promoting financial literacy. She left that firm as the Operations and Compliance Manager and moved to the Jacksonville Beach area. Gabbie enjoys trying new things, dancing in the rain, and Italian food.

Stacey Tuthill

Client Service Coordinator

A Jacksonville native, Stacey Tuthill holds a degree in Business Leadership from the Baptist University of Florida. She lives in Jacksonville Beach with her husband and their golden retriever. Outside of work, she enjoys playing tennis, cooking, and hosting friends and family.

Brooke Holden

Wealth Engineer

Brooke Holden joined the DEM team as a Wealth Engineer in 2026. She has a Bachelor of Arts degree in Economics from Michigan State University. She started her professional background in accounting and then moved to the financial services industry in 2019. She is a Certified Financial Planner and has a passion for helping people understand and optimize their financial situation. Outside of work, Brooke enjoys spending her time with her dog, staying active, and trying new restaurants.