Under normal circumstances, the fund primarily invests in equity securities. For security selection and portfolio construction, Principal Global Investors, LLC ("PGI") uses a proprietary quantitative model designed to identify equity securities in the S&P 500 Growth Index that exhibit growth characteristics, including higher quality, growth potential, and pricing power. "Higher quality" means securities that PGI believes possess higher quality characteristics relative to their peers, measured by profitability, earnings quality, balance sheet strength, and solvency.