In finance, a block trade refers to a large-scale transaction involving a minimum quantity of 500,000 or a value of at least Rs. 5 crores. These trades are conducted through the Block Deal window during a specific 35-minute time frame between 9.15 am and 9.50 am. This allows for efficient execution of high-value trades, providing liquidity and stability to the market. Understanding the concept of block trades is crucial for any investor looking to navigate the world of finance.