Meet the Staff

Maria Lettini, CEO

Maria Lettini is the Chief Executive Officer of US SIF: The Sustainable Investment Forum. She joined US SIF in May of 2023 and is an innovative leader within the fields of sustainability and finance.  She is recognized for building meaningful partnerships across the capital markets value chain to address some of the world’s most critical, and financially material, environmental and social challenges.

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Most recently, Maria led the FAIRR Initiative. During her six years at FAIRR, she and her team ambitiously drove the narrative around the risks and opportunities in the global protein supply chain with the aim of directing capital towards a more sustainable and equitable food system. Under her tenure, the FAIRR investor network grew to over $70 trillion in combined assets and FAIRR’s expert research reframed the investor narrative on animal agriculture and sustainable protein.

Prior to joining FAIRR, Maria worked for the UN-supported Principles for Responsible Investment (PRI) raising awareness of material ESG issues with institutional investors. Maria started her career in global finance and capital markets, working at both J.P. Morgan and Deutsche Bank. She has served on the Sustainability Accounting Standard Board Standards Advisory Group. She is also a member of the Intentional Endowment Network’s (IEN) Steering Committee.

Maria is based in Washington DC but has lived and worked in San Francisco, New York, Madrid and London. She holds a MA (Distinction) in Environment, Politics and Globalization from King’s College London and a BA in International Business, Latin American Studies and Spanish from San Diego State University.


Bryan McGannon, Managing Director
Bryan serves as US SIF's  Managing Director. Bryan leads the staff on executing the organization's strategic priorities and is US SIF's lead representative advancing the interests and perspective of the sustainable investment community with policymakers and stakeholders. Bryan also oversees US SIF's programming.
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Prior to joining US SIF in 2017, Bryan brought 20 years of policy and advocacy experience, most recently as Policy and Engagement Director for the American Sustainable Business Council, where he directed the policy team for a wide range of issues related to sustainability in business and the economy and served on the executive team.  

Prior to joining the American Sustainable Business Council in 2011, Bryan served as State Director in Ohio for the Alliance for Climate Protection's Repower America campaign. Bryan's political campaign experience spans presidential campaigns, congressional races, and local ballot initiatives. Bryan received his B.A. in Political Science from the University of California, San Diego.


Michael Young, Director of Education and Outreach

Michael joined the US SIF team in the fall of 2016, bringing over twenty years of financial services expertise. Michael is responsible for education and membership functions. He leads education initiatives, including US SIF courses and private training services and develops educational materials. Michael also manages membership relations, interacting with US SIF members and prospective members, an array of financial professionals and associations as well as the press.

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He presents frequently on sustainable investing at industry events and enjoys sharing the work of US SIF and its membership on podcasts and radio programs. Michael’s comments have appeared in the Wall Street Journal, Forbes, Investment News, and Bloomberg, among other publications.
Prior to joining US SIF, Michael worked in mutual funds, separately managed accounts, closed-end funds, and exchange-traded funds. His clients ranged from registered investment advisors and financial planning firms and broker-dealer firms to registered investment companies and hedge funds. His responsibilities included product development, relationship management with sub-advisory asset management firms, institutional sales, portfolio construction consulting, national accounts management, and advisor education. While at AdvisorShares, Michael helped launch the first actively managed fossil fuel free ETF. Previously, his time in financial services was spent with ING Investment Management and the Private Client Group at Merrill Lynch. Michael earned a bachelor’s degree from 
UC Davis.

Rachel Curley, Director of Policy and Programs

Rachel leads US SIF's policy and programming work to advance the interests and perspective of the sustainable investment community with policymakers and stakeholders. Rachel brings significant organizing, coalition building and public policy experience to the role.
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Before joining US SIF, Curley worked for seven years as democracy advocate for Public Citizen’s Congress Watch division, where she supported Public Citizen’s work on democracy and investor protection issues. In this role she led advocacy coalitions supporting corporate political spending and ESG disclosure.

Curley started her career as the program coordinator for Doctors for America, where she led the charge on several of the organization’s major campaigns. Curley graduated from Indiana University Bloomington with a bachelor’s degree in political science and philosophy.


Jun Han, Senior Research Manager

Jun serves as the Senior Research Manager of US SIF: The Sustainable Investment Forum. He is responsible for developing US SIF’s research strategy, delivering research outputs, strengthening US SIF’s expert voice, highlighting best practice, and fostering external collaborations and partnerships.
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Prior to joining US SIF, Jun has worked across international organizations (World Bank and IFC), nonprofits (Independent Sector and Halcyon House), and universities (Georgetown, Oxford, UPenn, UMD, and GMU), spanning research, teaching, consulting, and management roles. Most recently at the World Bank Group, Jun has conducted research and portfolio reviews on a variety of ESG or sustainability issues, especially on E (climate change, green bonds, risk financing, and water) and S (social entrepreneurship, disability inclusion, youth employment, and elderly care).

Jun holds a Ph.D. in Sociology from University of Oxford, and a Master of Laws in Sociology from Peking University. He received a Senior Research Fellowship and a Post-Doctoral Fellowship from Georgetown University, and a Summer Doctoral Fellowship from University of Pennsylvania.

Since 2010, Jun has co-authored 3 books, published 21 journal articles and chapters, and delivered 32 consulting reports to international organizations, nonprofits and think tanks. 

Yemi Asfaw, Manager of Finance and Operations 
Yemi Asfaw is Finance and Operations Manager and supports the operations, finance, membership and HR functions of US SIF.  She is responsible for accounts receivable and accounts payable functions as well as general office management and provides back-end administrative support to our programs.
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Yemi has significant experience in finance and operations, spending more than 12 years at the Institute for Security Studies (ISS-Africa), a non-profit research firm with headquarters in Pretoria, South Africa.  Based in Addis Ababa, Ethiopia, Yemi managed the organization from the start-up stage by developing policies and procedures, harmonizing internal policies with host country regulations and rules, providing inputs for strategic planning, and networking with host country government officials as well as other institutions. Yemi received a Bachelor of Arts from Addis Ababa University College of Commerce and a Master of Business Administration (MBA) from Sikkim Manipal University, India.

Jacob Koerner, Membership Services Assistant
Jacob joined US SIF in 2023 as Membership Services Assistant, bringing seven years of experience working with membership-based organizations. Key responsibilities include standardizing membership communications and materials, producing member invoices, assisting with education and events planning, and providing ongoing administrative support of the membership database.
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A Maryland native, Jacob graduated from Towson University in 2020 with a B.S. in Political Science, having taken courses in economics, international relations, and U.S. politics.