“I spend much more time on the balance sheet than on the income statement. Wall Street actually doesn't pay much attention to the balance sheet, but before reviewing the income statement, I will thoroughly study a company's balance sheets from the past 8 to 10 years.”

His core reason is only one: the reliability of the data.
“Compared to the income statement, many items on the balance sheet are harder for companies to hide or manipulate.”
Finally, he also clarified the significance of paying attention to the balance sheet:
“There is so much information that can be mined from it. In my opinion, the value of the balance sheet is far greater than most people realize.”