KKR is short for Kohlberg, kravis and Robert. Kohlberg is the oldest of the three, and began to engage in acquisition transactions as early as the 1960s. At that time, "Bootstraps" technology existed, including some features of modern leveraged buyout (LBO), which mainly involved British and American small enterprises with assets ranging from several hundred thousand dollars to several million dollars after World War II. When investors buy the equity of the target company, they usually turn it into a private company and invest the buyer's own money as little as possible in the transaction, so it is best to find a company with high cash flow characteristics. The so-called "shoelace acquisition" is to pull the company out of debt like "shoelace" and make the company more efficient. Colbert's pioneering work is to bring the management of the target company into "shoelace acquisition" and become a partner of the financial acquirer.