Aditya Agarwala, Co-founder & Director of Invest4edu, emphasizes the importance of knowing when to exit a stock in order to make money. He suggests considering both fundamental and technical parameters when deciding to sell. Agarwala recommends booking profits in sectors that have experienced significant gains, such as the Nifty PSE Index, midcap and smallcap indices. He also advises investors to trim their exposure in railway stocks, PSE names like REC and PFC, defence and shipyard stocks, and certain PSU banks.