Retained earnings

Retained earnings is the cumulative total of all net income the company has generated since inception minus all dividends and share repurchases paid out to shareholders over that same period. It represents the portion of historical earnings that has been reinvested in the business rather than returned to owners.

It is the single line on the balance sheet that most directly connects the income statement to the balance sheet. Every dollar of net income earned in a period increases retained earnings, every dividend paid reduces it, and the ending balance carries forward into the next period as the starting point. This makes it the running historical ledger of how much of the company's cumulative profitability has been retained and compounded within the business.

A large and growing retained earnings balance is generally a sign of a profitable business that has consistently earned more than it has distributed. An accumulated deficit, which is a negative retained earnings balance, signals that cumulative losses have exceeded cumulative profits since inception. This is common in early-stage, capital-intensive, or restructured businesses that have absorbed significant losses before reaching profitability.

Retained earnings is the primary source of internally generated equity financing. Rather than issuing new shares or taking on debt, a profitable company can fund its growth entirely from the earnings it retains. This form of self-funding avoids dilution and interest costs and is one of the hallmarks of a high quality compounding business.

The payout ratio, dividends divided by net income, and its complement the retention ratio measure how much of each period's earnings are being returned versus retained. This decision reflects management's assessment of the available reinvestment opportunities relative to the returns shareholders could achieve deploying that capital elsewhere.

Warren Buffett famously used the retention ratio as a quality filter, arguing that a company should only retain earnings if it can generate at least one dollar of market value for every dollar retained. This test distinguishes genuine compounders from businesses that retain capital simply because they lack the discipline to return it.