The e-commerce sector is experiencing significant tailwinds, with global online sales projected to reach $6.86 trillion by the end of 2025 and $7.89 trillion by 2028, driven by convenience and often lower prices compared to in-store shopping. Online sales already constitute about 20% of all retail transactions in the US, indicating substantial room for growth. This analysis compares five major e-commerce companies: Amazon, Mercado Libre, Shopify, Sea Limited, and Alibaba, based on revenue growth, operating profit margins, and valuation metrics (Forward P/E and Discounted Cash Flow). While all companies saw a slowdown in revenue growth post-pandemic, most have shown solid recovery. Alibaba had the slowest revenue growth at 3.7%, while Mercado Libre, Sea Limited, and Shopify all grew above 30%. Operating profit margins have shown improvement across the board, ranging from approximately 8.5% for Sea Limited to 13% for Shopify, with Amazon approaching 12%. Based on a combination of growth, profitability, and valuation, Amazon is considered the best e-commerce stock, with an intrinsic value of $266.79 compared to a current market price of $239.12. Mercado Libre is also attractive, with an intrinsic value of $2,759.17 against a current price of $2,075.01. Sea Limited appears undervalued at $145.35 intrinsic value vs. $121.42 current price. Alibaba is deemed fairly valued but with slow growth and geopolitical risks (intrinsic value $162.97 vs. current $165.40). Shopify, despite investor enthusiasm and an asset-light model, is significantly overvalued with an intrinsic value of $83.85 compared to a market price of $155.81, making it the least appealing investment among the five at current prices.