Catalyst days is the count of trading days until a binary event for a pharma or biotech ticker — Phase 3 trial readout, FDA approval decision, or major regulatory ruling — that historically moves the stock 30% or more in a single session. Under 90 days is imminent; over 365 is distant enough that current pricing already reflects most of the risk.
Pulled from ClinicalTrials.gov primary completion date for active Phase 3 trials. <90 days = imminent (size positions smaller). 90-365 = mid-term. >365 = distant (binary risk far enough that current pricing already reflects most of it).