The book-to-market ratio’s numerator adds assets and liabilities differing in risk. We propose a test for the value premium and its sources. Individual balance sheet holdings are divided by firm size. When associated risk premium coefficients are equal, an overall book-to-market is appropriate. Otherwise, there are different risks in assets and liabilities. For U.S. firms, for four decades since 1980, the excess return is regressed on seven ratios relative to size for cash, receivables, tangibles, intangibles, payables, short and long-term debt, and controls. The seven value premiums are not equal. Firms earn higher returns for cash and receivables and lower for short-term debt. Tangible and intangible assets earn no value premium.