Optimum Small-Mid Cap Growth Fund Class I (OISGX) is an open-end mutual fund that seeks long-term growth of capital by investing at least 80% of its net assets in securities of small- and mid-market capitalization companies, primarily common stocks of U.S. companies with growth characteristics; it may also invest in other securities deemed suitable by its sub-advisors. The Fund is managed through a multi-manager approach by Delaware Management Company, with sub-advisors Peregrine Capital Management, LLC, which employs fundamental research focused on high-growth companies undergoing significant fundamental change and is responsible for portfolio managers including Paul von Kuster (since April 2016), Ryan Smith and Samuel Smith (since January 2021), and Allison Lewis (since July 2023); and Principal Global Investors, LLC (Principal Dynamic Growth), which applies a "Fundamental Momentum and Positive Surprise" philosophy targeting small- to mid-sized companies producing better-than-expected results, led by portfolio managers Christopher Corbett (since July 2017) and Marc Shapiro (since July 2020). The Fund's portfolio is diversified across sectors such as technology (22.67%), industrials (22.10%), healthcare (19.55%), consumer cyclical (12.45%), and financial services (12.43%), with top holdings including Celsius Holdings Inc., Lazard Inc., Trimble Inc., Rambus Inc., and iRhythm Technologies Inc.; it maintains approximately 95.45% in U.S. stocks, 3.76% in non-U.S. stocks, and minimal cash. Launched on August 1, 2003, and domiciled in the United States with total net assets of approximately $736 million for the institutional share class, the Fund is available primarily to U.S. investors through financial intermediaries, with a net expense ratio of 1.19% reflecting contractual waivers through July 30, 2026. Recent developments include the addition of Allison Lewis to the Peregrine sub-advisory team in July 2023, enhancing fundamental research capabilities; ongoing expense waivers by the manager to cap operating expenses; and sustained portfolio turnover of around 132%, supporting active stock selection amid small growth market dynamics as of late 2025.