The present invention is directed to a catalyst composition for FCC which has high efficiency in the production of light olefins while maintaining the bottoms conversion. The catalyst composition is prepared by: a) ex situ activating an olefin-selective zeolite with at least 10 wt % of a phosphorus-containing compound, calculated as P2O5 based on the total amount of olefin-selective zeolite. b) combining the activated olefin-selective zeolite with 10-40 wt % catalytic cracking component, binder, and 0-25 wt % silica in a slurry, so that the total amount of amorphous alumina present in the final catalyst composition is at least 10 wt %, and c) spray-drying the slurry to form catalyst particles.