“Even with the bundling and splitting of tranches, Wall Street needed more mortgage borrowers, so it created the subprime market. These were loans to borrowers who did not meet the underwriting standards set forth by the GSEs, or “prime” loans. Subprime borrowers were riskier borrowers, either because they had fewer assets, lower credit score, or lower incomes. But in finance, higher risk is rewarded with higher yield, so mortgage brokers made even higher premiums from subprime loans.”