Have you ever wondered why the stock market swings up and down so much? One big reason is the activity of big investors—Foreign Institutional Investors (FII) and Domestic Institutional Investors (DII). These are the market’s heavyweights, and their moves can make a huge difference in stock prices. But what does this mean for you as a retail investor? Should you follow their moves, or is there a smarter way to invest? Let’s break it down in simple terms.