 Investors on Wall Street are gearing up for a new corporate earnings season, with big financial firms set to report their results this week. NPR's Rafael Nam has more. Companies are starting to report their earnings for the period between April to June. The earnings are an important check on the health of the U.S. corporate sector. And they're coming at a time when investors are feeling optimistic about the economy, with the Dow Jones Industrial Average surging last week.