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Kara Marquez CFP®

I am originally from a small town in Upstate New York called Sodus. I attended American University in Washington, DC. Upon graduation in 2000, I joined a venture capital firm, TVM Capital, in San Francisco. It was in this dynamic and vibrant environment where my love of entrepreneurship and investing was born. 

The company asked me to relocate to Boston where I lived for 8 years before moving to Orange County, California in 2010. I accepted a position with Fidelity Investments in the Mission Viejo office in 2011 where I worked until 2014 when I was recruited to join JP Morgan Securities. In working with high net worth individuals I became passionate about incorporating all the different aspects of a client’s financial situation. This led me to earning my CFP®designation.

In order to work with my clients in a pure Fiduciary capacity, I joined Nautilus Advisors and had the opportunity to open an Orange County office. 

I live in South Orange County with my husband Michael and our son Easton. When I am not working, I enjoy short weekend trips along the beautiful coast of California, running, and taking Easton to the pool and playground. 

Dan Callan MBA

My career in the investment business began while I was an Economics major at the University of CA, San Diego.  I interned at Prudential Securities and accepted a position with them when I graduated in June 1999, which turned out to be a fascinating time in the capital markets.  The NASDAQ and S&P 500 peaked less than a year later, ushering in the Tech Bubble, which gave me a healthy perspective of risk and valuation early in my career.   

While pursuing my MBA a few years later at Arizona State University, I was able to work at a mutual fund company, as well as a large institutional fixed income firm where I helped community banks manage their bond portfolios.  When I finished my studies, I found that I missed both CA and helping individuals and families manage their wealth.  I decided to return to CA and work with private clients, which I have been doing ever since... first with Charles Schwab, then JP Morgan Chase, and now with Nautilus Advisors.  

Having worked with both individuals and institutions, in both bull and bear markets, I have a healthy appreciation of the time and attention that goes into properly managing wealth which starts with crafting a financial plan, and then executing the plan as the business cycle fluctuates.  This philosophy led me to feel that the best environment to do this was as an independent advisor working in a purely fiduciary capacity.  The opportunity arose to open the Orange County office of Nautilus Advisors, where I can fully focus on incorporating the broadest possible range of investments into customized client solutions. 

I’ve lived in the Talega neighborhood of San Clemente for 11 years, have two children, Cameron and Jack, and in my free time I enjoy the amazing outdoor lifestyle that Southern California has to offer.   

Michael Behner CFP®

Born and raised in San Diego, I come from a third generation San Diego family. The Navy originally brought the Behner family to San Diego with my great grandfather serving as Rear Admiral stationed on North Island. My grandfather served as executive officer at the 32nd St. Navy Base. Both commanded ships in the Theatre of the Pacific in WII and my great grandfather also serving in WWI. My father, grandfather and great grandfather all went through basic training at the Naval Training Center in Point Loma at what is now known as Liberty Station.

During pre-law studies at UCSD I interned with Merrill Lynch and immediately found a passion for the capital markets, more so than Law. Prior to graduation I procured a position with Prudential Securities in their Financial Advisor development program. Of 138 trainees I was ranked number one at six months, one year and two years. The bear market of 1999-2002 took its toll and upon graduating at the end of year two, I was one of only three left in their program nationwide. Early in my career I took an interest in fixed income while tech and Internet stocks captivated most others. I was the youngest Financial Advisor in the Prudential Securities system approved to trade the highly complex collateralized mortgage obligations of CMO’s and CDO’s.

I took an offer to run the Wealth Management arm of several Citibank branches in 2004 but quickly found the bank environment was not the right fit. A year later I accepted a management position with the investment arm of New England Financial, an insurance company with roots to 1897. At New England Securities I was responsible for running the San Diego branches’ investment book and also served on the investment committee defining investment policy and asset allocation for the five-state firm. I was also responsible for new advisor development and training, a role I truly enjoyed.

Although I took great pleasure in my five years with New England Financial, establishing my own firm was always my long-term vision. Tom Brenner and I opened shop in September of 2010 as Nautilus Advisors LLC. Within two weeks we transitioned 99% of our clientele. We are thrilled with our move and feel that we now can create the platform the best serves our clients.

I am married to Melissa Williams, an adjunct professor of Literature at the University of San Diego. We have three young children, Maximus, Hagen, and our most recent addition, Gretchen. My interests include wine tasting and cooking, watching English Premier League soccer, cycling, surfing, golf (when I’m hitting the ball well) and playing sports with the kids.

Thomas Brenner CFP®

I have been a financial advisor for the last decade, beginning my career at New England Financial in San Diego and continuing to follow my passion in as a partner with Nautilus Advisors. Prior to joining New England Financial, I worked in the action sports industry in various sales and management positions.

Growing up in New Jersey, I spent my summers lifeguarding on the Jersey Shore. I attended a very unique high school on those same beaches, where my studies were focused on Marine Sciences. Continuing my education in Rhode Island, I received a B.S. Degree in English from the University of Rhode Island in 1994.

After graduating from college, I moved to San Diego and have made it my home since 1995. I’m married to Jennifer Brenner and have a step-daughter Kayla. I’m a long-time and passionate surfer and when I’m not working, I’m most often found enjoying the ocean.

Mark A. Halby, CFP®, AIF®

Financial Planner


I was born and raised in Northern California, one of five children, and the son of an insurance agent of 40 years. Growing up I have always looked up to my father and thought that I wanted to get into the insurance business like him. I moved to San Diego in 2004 to attend San Diego State University. While studying financial services, I learned about Financial Planning and immediately decided that it was the profession I wanted to pursue. So, in my senior year, I joined the local Financial Planning Association. That year I became a founding member of the Financial Planning Associations’ Student chapter at SDSU, and served as its first membership chair.

In 2008 I graduated from SDSU with a Bachelor of Science Degree in Business Administration with an emphasis in financial services. I began working as a Financial Planner with New England Securities immediately upon graduating. I spent 5 years with the firm and met a lot of great mentors, including my current partners at Nautilus. During my time there I also acquired two designations, CERTIFIED FINANCIAL PLANNER and Accredited Investment Fiduciary®.

In 2013, I decided that I wanted to run an independent practice, and found the opportunity at Nautilus Advisers. Today, I am still involved with the San Diego Financial Planning Association, serving on its membership committee. I greatly enjoy presenting to the SDSU student chapter on occasion, a role reversal from my time in college. In addition I am an active member of the SDSU Alumni Association.

Outside of the office, I am passionate about football and serve as a high school football official with the San Diego County Football Officials Association. Other hobbies include yoga, running, golf, and surfing.