Source text: The UK's Office for Budget Responsibility (OBR) inadvertently released its fiscal outlook ahead of Chancellor Rachel Reeves' budget statement, causing significant market volatility. The projections indicated an expansion of fiscal headroom to approximately £22 billion, attributed to tax hikes and increased public spending. This unexpected release led to fluctuations in the GBP/USD exchange rate, which ranged from 1.3125 to 1.3200, and UK 10-year gilt yields, which varied between 4.43% and 4.49%. The leak, resulting from a technical error, prompted market participants to reassess risks related to growth, inflation, and gilt supply. Target language code: fr Translation instructions: This is the news article content. Please maintain the original meaning.