A recession is a period of sustained negative economic growth. Kalshi defines a recession as one quarter of negative GDP growth, though other groups like NBER define a recession as two consecutive quarters of negative GDP growth. Using the second definition, US has had up to 48 recessions in its history. Some notable recessions include the 2020 COVID-19 recession, the 2007-2009 Great Recession, the Great Depression and the Panic of 1873 (which still holds the record for most consecutive quarters of negative GDP growth).