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Our Story



A mathematical theorem, to us, represents what can be proven through experience, deduced from what is known or established through the scientific method.

Picture of theorem wealth management team

We find that speculation and emotion generate stress, but structure and consistency reduce it.

Theorem is an independent full-service wealth management firm founded on the belief that for clients to feel confident in their finances, it takes an analytical approach that simplifies the complex. As fiduciaries we work solely in the best interest of each client, providing a systematic process to help mitigate both risk and stress on the way to a well-planned retirement.

Our Culture

A simple missionMaking a differenceMeaningful client relationshipsstriving for better
Forbes best in state wealth advisors 2019 graphic

Our Leadership Team

Johnathan Rankin, Theorem Founder and CEO

Johnathan Rankin

Founder and Chief Executive Officer

Melissa Rankin

Senior Wealth Advisor

Melissa Rankin, Senior Wealth Advisor

Johnathan Rankin founded Theorem Wealth Management after a 12-year tenure at Merrill Lynch, where he was a First Vice President. He also held numerous leadership roles, including Resident Director, where he oversaw an office managing $9 billion in client assets. He found that he was able to deliver the most value to clients by systematically managing not only their plans and investments, but also their stress and anxiety around goals like retirement. He formed Theorem Wealth Management to offer this service platform to a client base of engineers and professionals, as well as institutions and non-profit organizations.

Melissa Rankin joined Theorem Wealth Management after 15 years in the financial services industry, including over 10 years at Merrill Lynch. As Senior Wealth Advisor at Theorem Wealth Management, Melissa specializes in financial planning and relationship management.

Johnathan is a Chartered Retirement Planning Counselor℠ and a graduate of California State University, Sacramento, where he earned a degree in Economics with a focus on business management. In 2019 he was named a Forbes Best-in-State Next Generation Wealth Advisor*, an accolade that represents both quantitative and qualitative achievements in his work within the wealth services field.

In recent years, Johnathan has also been mentoring young children in the Big Brothers Big Sisters program and has spent time as a Wish Granter with Make-A-Wish. He lives in Dallas, Texas with his wife Melissa, their children Harvey and Emersyn, and their dog Julep.

Melissa studied Finance at Arizona State University and currently lives in Dallas, Texas with her husband Johnathan, their children Harvey and Emersyn, and their dog Julep.

“It’s uncertainty that is most responsible for the stress that develops around retirement. We’ve identified the things that reduce uncertainty, like communication and systematic planning, and we’ve excluded the things that generate it, like speculation and reactionary investing. The result is a process that helps you look forward to retirement as you prepare for it.”

Melissa Rankin
Senior Wealth Advisor

*Source: Forbes “Best-in-State Next-Generation Wealth Advisors” list, September 4, 2019. Forbes “Best-in-State Next-Generation Wealth Advisors” list was developed by SHOOK Research. Advisors considered for this ranking were born in 1980 or later with a minimum 4 years relevant experience; advisors have: built their own practices and lead their teams; joined teams and are viewed as future leadership; or a combination of both. Ranking algorithm is based on qualitative measures: telephone and in-person interviews, client retention, industry experience, credentials, review of compliance records, firm nominations; and quantitative criteria, such as: assets under management and revenue generated for their firms. Investment performance is not a criteria because client objectives and risk tolerances vary, and advisors rarely have audited performance reports. Rankings are based on the opinions of SHOOK Research, LLC and not representative nor indicative of any one client’s experience, future performance, or investment outcome. Neither Forbes nor SHOOK Research receives compensation in exchange for placement on the ranking. Forbes is a trademark of Forbes Media LLC. All rights reserved. Rankings and recognition from Forbes are no guarantee of future investment success and do not ensure that a current or prospective client will experience a higher level of performance results and such rankings should not be construed as an endorsement of the advisor.Chartered Retirement Planning Counselor℠ and CRPC® are registered service marks of the College for Financial Planning.

Why is it so important to
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part of our team?

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Thoerem Partner - Charles Schwab

Charles Schwab

We selected Charles Schwab as our custodial partner because of their immense platform and their stellar reputation for security and support. With nearly $4 trillion in client assets, they have been named by the United States government as one of the country’s nine systemically important financial institutions.

In addition to custody of client assets, Charles Schwab also provides important back office services to Theorem Wealth Management.

Thoerem Partner - Sanctuary Wealth

Sanctuary Wealth

Sanctuary Wealth is a hybrid financial firm defined by its unique open platform, Partnered Independence℠. Sanctuary has developed an elite network of advisors who, like Theorem Wealth Management, knew that independence was the best option for their team and their clients.

Through Partnered Independence℠, we’ve gained the freedom, flexibility and control of an independent fiduciary, yet we have the support systems we need to keep our focus on our clients, and we have access to the best-in- class specialists and resources we need to deliver a comprehensive wealth management experience.

Thoerem Partner - eMoney


As part of our commitment to clarity and transparency, we use eMoney Advisor’s breakthrough software to make it easy for our clients to view and analyze their financial data. The platform includes an intuitive interface that you can view on any device, and planning and collaboration tools that help simplify the wealth management process.

eMoney serves more than 2.9 million investors, tracks more than $2 trillion in aggregated assets and is used by 46 out of the nation’s top 50 broker-dealers.

"You shouldn’t have to depend on approximations or rules of thumb to plan your retirement. We pursue scientific accuracy to the fullest extent possible within each component of your plan, so that you can make informed and well-considered decisions that suit your particular needs."

Johnathan Rankin CRPC®
Founder and Chief Executive Officer

Picture of Johnathan Rankin, Theorem Founder and CEO

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We believe knowledge is the most powerful financial tool there is, so we take every opportunity to share ours with anyone who may benefit. Click on the links below to download digital versions of our recent financial guides.

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