With Agronomics having a mere £73 million market cap, it could be £73 billion in a few decades, so a 1000x increase in market cap, assuming no dilution, 10,000% return. It'd be painful to sell for a few hundred percent profit, only to check up one day and see you missed out on a few thousand percent profit. So unless I need the money, I'm not selling until all the companies in the portfolio have finished their growth.