Sentiment Without Structure: Differential Market Responses to Infrastructure vs Regulatory Events in Cryptocurrency Markets

We investigate differential market responses to infrastructure versus regulatory events in cryptocurrency markets using event study methodology with 4-category event classification. From 50 candidate events (2019–2025), 31 meet inclusion criteria across Bitcoin, Ethereum, Solana,and Cardano. We employ constant mean and market-adjusted models with event-level block bootstrap confidence intervals that properly account for cross-sectional correlation. Our primary comparison focuses on negative-valence events: infrastructure failures (8 events) versus regulatory enforcement (7 events). Infrastructure failures produce mean Cumulative Abnormal Return (CAR) of −7.6% (95% CI: [−25.8%, +11.3%]) and regulatory enforcementproduces mean CAR of −11.1% (CI: [−31.0%, +10.7%]). The difference of +3.6 percentagepoints has CI [−25.3%, +30.9%], p = 0.81—a null finding indicating markets respond similarly to both shock types when controlling for valence. Robustness checks confirm consistent results across window specifications, leave-one-outexclusion of major events (FTX, Terra), and alternative market model specifications. The 4-category classification addresses prior conflation of upgrades with failures. This exploratoryanalysis should be treated as hypothesis-generating. JEL Codes : G14, G18, G23