The smartest way to invest in stock market is to buy stocks is when a company first starts selling them to the public, or through an IPO. IPO stands for Initial Public Offering, and it's when a company offers its shares to the public for the first time after getting approval from the country's security exchange board. These IPO shares are usually cheaper. In my area, IPOs are sold for $1 each. Even when a company offers IPO for a premium price, it is just around $4. After the IPO ends, these shares can be traded on the stock exchange. Once IPO closes and the stocks are available for trading, the $1 or even $4 IPO begins to trade for a way higher amount. Their value goes up based on how well the company does with its revenue generation or how much demand for their stocks are in the stock market.
