A look at why getting added to the NASDAQ 100 hands a company a built-in flood of buyers — good for any stock that makes the cut.

• The NASDAQ 100 tracks the top 100 tech stocks, and hundreds of billions in funds copy it automatically.
• When a company joins the index, all those funds are forced to buy its stock, no choice involved.
• That forced buying creates billions in instant demand for the new addition.
• Getting in works like a money printer — sudden access to huge passive cash that has to buy the shares.

Outlook: Watch which companies get added next, since inclusion alone can push a stock sharply higher.