Legendary investor Warren Buffett primarily relies on calculating the intrinsic value of a business by analyzing its projected future free cash flows discounted back to the present day, a philosophy rooted in the principles taught by Benjamin Graham. Rather than chasing short-term market momentum, he focuses heavily on qualitative factors like a company's enduring economic moat, pricing power, quality of executive management, and consistent return on equity. He purchases shares only when the prevailing market price trades at a substantial discount to his calculated intrinsic value.