Ruta Ziverte, a Partner of William Blair Investment Management, LLC, has co‑managed the Bond Fund since 2021, has co‑managed the Income Fund since 2020, and managed the Low Duration Fund since 2021. Ms. Ziverte oversees the fixed income team at William Blair. She was responsible for developing and executing our fixed-income growth strategy (in conjunction with other members of the team), team leadership, and select portfolio management. Before joining William Blair in 2019, Ruta worked at Oppenheimer Funds, where she was the portfolio manager for the Global High Yield Fund and co-portfolio manager for the Global Strategic Income Fund. She also led a team of fixed-income credit analysts. Before joining Oppenheimer Funds in 2015, Ruta worked at GE Asset Management, where she most recently served as executive managing director and high-yield portfolio manager. Previously at GE, Ruta was a team leader and senior analyst, co-managing a leveraged finance research team, and was responsible for developing and implementing the firm's credit processes and procedures. Earlier in her career, Ruta was a credit analyst with Citigroup/Travelers Life and Annuity. She also worked at Phoenix Investment Partners. Ruta received a B.S. Finance from the University of Latvia and an M.B.A. from Rensselaer Polytechnic Institute.

Vesta Marks, CFA, an Associate of William Blair Investment Management, LLC, most recently was a portfolio manager and Managing Director of Fixed Income and Risk Management at Tortoise Capital Advisors. Before joining Tortoise in 2019, he served as Executive Director and Portfolio Manager at Palmer Square Capital Management LLC from 2015 to 2018. Prior to Palmer Square, Vesta was a Portfolio Manager at Semper Capital Management from 2007 to 2014. Vesta joined Semper Capital Management in 2003. Mr. Vesta is a member of the CFA Institute. He is also a member of the Chartered Alternative Investment Analyst Association. Education: Bachelor of Science degree in mathematics from the Massachusetts Institute of Technology (MIT). Vesta has many years of experience in the financial services industry, primarily focused on the analysis and portfolio management of securitized debt instruments. Vesta has primary responsibility for asset-backed and commercial mortgage-backed analysis and trading as well as responsibility for analysis and trading of short duration securities, non-agenc and agency RMBS. He also served as a portfolio analyst at Earnest Partners, modeling and analyzing portfolios of small business loans, GNMA project loans and RMBS. In addition, he formerly worked as a sell-side analyst at Independent Banker's Bank of Florida, where he analyzed banks' securities portfolios, worked with ALM committees, and assessed the valuation and risks of loan portfolios.