<p>This article investigates the structural heterogeneity of inflation in Brazil by analyzing persistence, trend, and volatility across key disaggregated components (core, services, free-market, and monitored prices) using the Extended National Consumer Price Index as a benchmark. Based on monthly data from August 1999 to December 2024, the study employs fractional integration and unobserved-components stochastic volatility outlier-adjustment models to test the claim of a dichotomy between persistence and volatility. The results reveal that the Extended National Consumer Price Index exhibits long-memory persistence (<i>d</i> = 0.31), and inertia primarily demand-driven, as core (<i>d</i> = 0.57) and services (<i>d</i> = 0.44) inflation show the highest persistence levels, while monitored prices exhibit the lowest (<i>d</i> = 0.19). Although services inflation exhibits a smoother trend, its persistence has risen over the last decade, converging with core levels. Furthermore, aggregate volatility is largely a transitory phenomenon driven by several idiosyncratic outlier episodes in monitored prices. Permanent volatility remains generally stable across most groups, peaking in monitored prices, due to supply shocks, and reaching its lowest in services, reflecting demand-side stability. A key policy implication is that monitoring sectoral inflation must be coupled with an analysis of permanent and transitory volatilities to fully capture nuanced trend dynamics often masked by aggregate data.</p>