The Longs Peak

Our core values are why we’re the best at
what we do. Here’s a look at why you’re
going to want to choose Longs Peak.

Who we are.

Longs Peak Advisory Services, LLC (“Longs Peak”) was established to provide the investment management community with guidance, education, and support relating to GIPS compliance and investment performance. While a Partner at a large GIPS verification firm, our founder, Sean Gilligan, recognized that many of his clients lacked the resources necessary to become GIPS compliant and get through their GIPS verification in a timely manner.

With his entrepreneurial spirit and determination to help these firms, Sean started Longs Peak. Sean and his team have extensive experience helping firms navigate the GIPS standards and calculate investment performance. Having worked with hundreds of firms of varying sizes across North America, Europe, the Middle East, and Asia, Longs Peak’s consultants understand the unique needs and challenges firms face and are available to share this knowledge and experience with your firm.

Sean P. Gilligan

CFA, CPA, CIPM – Managing Partner

Founder, firm visionary, and master of simplifying the complex. Sean has over 20 years of experience in the investment industry, with the last 16 years focused specifically on investment performance and GIPS compliance. From the front office to the back office, Sean has seen it all and has a deep understanding of how investment firms and asset owners operate. Sean is passionate about helping firms understand complex topics. With his unique ability to breakdown complicated topics into simple, digestible terms, Sean strives to make GIPS compliance easy enough for any firm in the world to comply.

Jocelyn Mullis

CFA, CIPM - Partner

Co-founder, keeper of employee experience, and accountability guru. Jocelyn has 14 years of experience in the financial services industry. She is passionate about client service and project management and has worked with some of the world’s largest financial institutions. After serving as a Manager at Ernst & Young, Jocelyn switched gears to become a mother, but her heart could never fully leave her professional career behind. Helping start Longs Peak was one of the best decisions she has ever made as she loves leading the firm’s internal initiatives, challenging the executive team to meet and exceed goals, and helping develop our team of GIPS standards superstars.

Matt Deatherage

CFA, CIPM – Partner

Trailblazer, champion of training, and master of all things GIPS. Matt joined Longs Peak in the fall of 2019 and has over 7 years of experience working specifically with the GIPS standards as a verifier and consultant. Having worked for the largest verification firm for 6 years, he has the experience necessary to help firms of all shapes and sizes implement the GIPS standards. Matt is a seasoned GIPS consultant and is exceptional at client service and leading teams. His ability to coach our team and lead our clients through their GIPS engagements is unparalleled.

Cameron Payseno

CIPM – Manager

Project manager, client process specialist, and chairman of fun. Cameron joined Longs Peak in 2018 after graduating from the University of Colorado where he was an Evans Scholar and graduated with an Honors degree in Quantitative Economics. With a love for statistics and client engagement, Cameron is well suited to manage engagements of all kinds. Cameron is a catalyst of entertainment and ensures his fellow teammates find joy in what we do every day.

Sara Celapino

Sara Celapino


Mathematician, data slayer, and provider of exceptional client service. Sara joined Longs Peak in the Spring of 2020 while finishing her degree in Financial Mathematics at Robert Morris University in Pennsylvania. Sara brings programming knowledge to Longs Peak and assists in making client processes and technology more efficient and effective.  She is a natural project manager and quick learner, operating with excellence on all levels.  Sara is a Level I candidate in the CFA program.

Tiger Zu

Tiger Zu


Data enthusiast, humble craftsman, and continuous learner (but not a golfer), Tiger joined Longs Peak in 2020 after graduating with distinction from the honors program at Colorado State University.  Tiger’s experience in both economics and investment finance make him an asset to Longs Peak. His passion for data analysis ensures that performance statistics are accurate and in compliance with the GIPS Standards, while his ideas for improvement increase the accuracy and efficiency of the compliance process. Tiger is a Level I candidate in the CFA program.

Chandler Patterson

Chandler Patterson


Information architect, organization specialist, and excellence operative. Chandler began working for Longs Peak as an intern in 2021, while completing a BS in Business Administration with an emphasis in Corporate Finance & Computer Information Systems at Colorado State University.  Chandler’s foundation in technology helps Longs Peak maintain its proprietary software and bridge the gap between client service and AI.  Her excitement and motivation for solving problems and gaining knowledge brings energy to our growing team.

Cally Chenault

Cally Chenault

Operations Manager

Positivity powerhouse, efficiency devotee, and sparkling conversationalist. Cally joined Longs Peak Advisory in 2021 after several years of serving as a household engineer (aka Mom) and following her spouse around the world.  Landing here in Colorado, she realized that it would be a shame to let her organization skills benefit only one household, and consequently brought her talents to Longs Peak to manage office operations. Lending support to team members and assuring that the business back-office runs smoothly, Cally finds satisfaction in creating structure and harmony.

What we believe in.

Acting with Integrity
  • We uphold the highest levels of integrity in the financial industry through our work, interactions with our colleagues and our clients
  • We behave ethically and honestly and are not afraid to admit to mistakes
  • We are transparent about our weaknesses and aren’t afraid to ask for help from our teammates
  • We always do what’s right, even if it means risking looking bad or potentially losing business – the integrity of our work is paramount to what we do
  • We treat others with respect and have zero tolerance for behavior that is offensive or undermines our values
Using Prudent Judgment
  • We seek to make wise decisions (technical, business and people-related) even when the outcome is uncertain
  • We think and act strategically, not just about our work, but also in our interactions with others
  • We seek to identify and prioritize what must be done now vs. what can be done later
  • We trust our team and empower our teammates to use their judgment in their work
  • We value accuracy and completeness over speed – we do not need to answer all questions immediately if research is necessary to answer a question properly
  • We are eager to learn and adapt quickly
Operating with Excellence
  • We are dedicated to providing exceptional client service and are committed to making our clients’ lives easier through the work that we do for them
  • We seek to avoid making mistakes that undermine the quality and integrity of our work
  • We listen carefully, instead of reacting quickly
  • We strive to continuously improve what we do so that mistakes can be eliminated or at least minimized
  • We maintain our composure in stressful or upsetting situations
  • We challenge the status quo when warranted and never stop searching for ways to improve our business, our clients’ business and to make everyone’s lives easier
Simplifying the Complex
  • We make GIPS compliance attainable for any organization in the world
  • We help minimize complexity and simplify what we do for our clients as well as what we do internally
  • We believe in providing practical advice that simplifies complex topics and delivers them in plain language
  • We continually build new and improved tools and processes to improve efficiency
  • We are concise and articulate in verbal and written communication with clients and team members
Being One Team
  • We make time to help our colleagues and share information and knowledge openly and proactively
  • We demonstrate our values to our colleagues and are committed to being someone that can be relied on
  • We treat people with respect, regardless of who they are or whether our opinions differ
  • We empower each other through trusted collaboration
  • We accomplish amazing amounts of meaningful work
  • We take calculated risks and operate with a ‘can-do’ attitude
  • We question actions that are inconsistent with our values
  • We strive to learn new things outside of our comfort zone
Living Your Best Life
  • We take time to take care of our physical and mental health
  • We manage stress by finding an appropriate work/life balance
  • We take full advantage of our paid-time-off and wellness benefits
  • We support each other to meet personal goals
  • We find ways to have fun at work
  • We celebrate wins and learn from losses

Interested in joining our team?

We’ve got the information you need.

There’s reason to be excited!

With our help, things are going to be a whole lot easier for you.
Talk to one of our GIPS consultants or performance experts today and let’s get started.