Much has been made of whether or not day trading serves a useful purpose for markets and for society in general, “YES”, it is true, traders are aggressively looking to profit from the markets and from other investors. They don’t add much value in terms of providing capital for the function of free capitalist society or the companies. As such, they provide a useful function by making a market, by buying here and selling there, by creating liquidity, that is, buying and selling choices, in the market. They help define the best price for the product and to make it transparent – for everyone to see.
The presence of a large number of traders will reduce the “spread,” that is, the difference between the bid, or buy, price and the ask, or sell, price to a minimum. Contrast this to a situation where there was only one dealer in a market – the dealer could make the spread almost anything he wanted and move the price a this own free will. The presence of traders makes the markets move more in line with true supply, demand, makes price fair, and transparent to everyone. So, while every vocation has it rogues, the profession of securities trading serves a useful purpose in moving the market of capitalism forward.