Why have HFT?

HFT aims at getting many transactions per second. In this way, companies can react more quickly to a changing market. They can take advantage of more opportunities than they would have without this speed. Additionally, large institutions benefit from HFT by gaining a tiny but considerable advantage in exchange for delivering massive volumes of liquidity to markets. They place millions of orders that their systems are capable of placing. They help the market and, as a result, are able to boost earnings in their profitable trades and receive better spreads. Since the return is very low, they must complete many trades to benefit. On top of this revenue, they will gain rebates or discounted transaction fees, which are given by trading venues to make their markets more attractive to HFT firms.