Amazon.com (NASDAQ:AMZN) shares are rising due to continued gains in e-commerce market share and strong engagement from merchants and brands. Analyst, Richard Post, stated that many sellers have not raised prices despite higher oil and shipping costs, as they fear losing market share if they increase prices. He also highlighted signs of consolidation among Amazon’s top sellers, with data from Skai showing traffic per seller increasing by 31% since 2021, and new seller registrations fell 44% year over year in 2025, and the active seller base declined. The number of sellers generating over $100 million in gross merchandise value (GMV) has risen to 235, up from just 50 in 2021. Despite expanding 277 retail media networks, Amazon still holds about 79% market share with Walmart trailing at roughly 8%. Sales are increasing advertising budgets on Amazon due to strong results and AI-driven tools are becoming central to seller operations.