Infectious disease-focused biopharma stocks, tracked on the BioWorld Infectious Disease Index (BIDI), saw their collective shares roughly follow the path of broader markets like the Nasdaq Biotechnology Index (NBI) and the Dow Jones Industrial Average (DJIA) in early 2026. The BIDI ended April up 3.8%, followed by the DJIA with a 3.31% gain and 2.73% for the NBI, following a similar pattern to 2025.