Since the post-pandemic market rally, local and foreign investor participation in the Colombo Stock Exchange (CSE) has grown steadily. Despite this growth, the CSE remains undervalued compared to the regional peers, with a price-to-earnings (P/E) ratio of approximately 8x and a market capitalisation to GDP of 19%, signalling significant untapped potential for long-term capital allocation. One of the major causes for this is the lack of retail investor participation. Retail and novice investors face challenges in constructing diversified, risk-minimised portfolios due to low liquidity, the lack of awareness in the Sri Lankan capital markets, and the lack of tools and applications for portfolio creation and management. They often rely on ad-hoc advice or personal sentiment, resulting in suboptimal returns and heightened exposure to market fluctuations. This project proposes the ‘Equity Portfolio Builder' web application that empowers retail investors to build and manage risk-optimised equity portfolios across all CSE-listed companies. Grounded in Markowitz’s Modern Portfolio Theory, the application uses a quadratic optimisation engine to compute optimal weight allocations, minimising portfolio variance by analysing historical price data to generate covariance matrices. It features automatic portfolio rebalancing to adapt to changing market conditions and user goals. It is delivered through an intuitive, transparent interface that simplifies complex statistical processes to be accessible to average retail and novice investors. This tool democratises sophisticated portfolio construction, enabling retail and novice investors to make informed, data-driven decisions, bridging a critical gap in Sri Lanka’s capital markets by offering a cost-effective, self-directed solution to enhance investment management and encourage market participation.