This podcast is made by Ran Chen, who holds an EA license, Insurance and Securities licenses (Series 6, 63, 65), and the CFP® designation. He is passionate about opening access to high-quality exam preparation resources and helping learners prepare more effectively for professional certification exams. In this episode you will learn: • How credit rating scales define investment-grade versus speculative debt categories. • Why bond issuers exercise call features when prevailing interest rates decline. • The difference between call risk, reinvestment risk, and call protection. • How to apply the yield-to-worst rule for premium and discount callable bonds. • Disclosures required under NASAA model rules and state fiduciary standards. This podcast is an independent study resource for Series 66 candidates. Practice questions and additional study aids are available at https://open-exam-prep.com/practice/series66 and video lessons are available on YouTube at https://www.youtube.com/@Open-exam-prep . Sources checked: September 14, 2026 • https://www.nasaa.org/wp-content/uploads/2023/02/Series-66-Outline-June-2023.pdf • https://www.finra.org/registration-exams-ce/qualification-exams/series66