 LONDON--BUSINESS WIRE--Janus Henderson Group plc NYSEASX: JHG; JHG, the Group published its first quarter 2021 results for the period ended 31 March 2021. First quarter 2021 operating income was US192.5 million compared to US227.0 million in the fourth quarter 2020 and US332.4 million in the first quarter 2020. Adjusted operating income, adjusted for one-time, acquisition and transaction related costs, was US201.5 million in the first quarter 2021 compared to US231.7 million in 