GDP lands at 08:30 ET, quarterly, in three estimates for the same quarter. Only the first one moves anything.
The total value of goods and services produced. It is the broadest measure of economic output and the backdrop against which every other release is interpreted.
Growth determines how much room the Federal Reserve has. A strong economy tolerates tighter policy; a weakening one forces cuts. Both work through the rate path and therefore real yields.
Trading the revisions.
GDP is published three times for the same quarter — advance, second and third estimates. The advance reading moves price most because it contains the most new information. By the second revision the market has usually moved on, and the third rarely registers at all.
The advance estimate, and within it the consumer spending component — the largest and most policy-relevant piece.
The GDP price deflator arrives alongside and is an inflation measure in its own right, occasionally moving rate expectations when it diverges from CPI.