Which financial document provides insights into a company's profitability over a period?

The income statement is the financial document that provides insights into a company's profitability over a specific period. It details the revenues generated and expenses incurred during that timeframe, ultimately showcasing the net income or loss. This document allows stakeholders to assess how well the company is performing financially by analyzing whether it is generating profit or sustaining losses during the reporting period.

In contrast, the cash flow statement focuses on the inflows and outflows of cash, providing insights into the company's liquidity and cash management rather than direct profitability. The balance sheet offers a snapshot of a company's assets, liabilities, and equity at a single point in time, helping stakeholders understand the company's financial position but not its operational performance over a period. The statement of retained earnings tracks the changes in retained earnings over time, which does relate to profitability but does not directly report it like the income statement does.