Why did support for the Nazi Party and Communist Party grow after 1929?

The growth of support for the Nazi and Communist parties after 1929 was primarily driven by the catastrophic economic and social collapse caused by the Great Depression.12

Following the stock market crash of 1929, Germany faced severe financial instability as American loans were withdrawn, leading to widespread business failures and soaring unemployment, which reached six million by 1932. This crisis undermined the Weimar Republic, causing the collapse of the governing coalition and forcing the government to rely on emergency decrees.123

• Nazi Party: Adolf Hitler exploited the misery of the middle class and the unemployed through relentless propaganda and charismatic appeals, positioning himself as a savior who would restore Germany's greatness. He successfully scapegoated Jews and the republic for the nation's ills, while wealthy industrialists provided financial backing to support a right-wing, anti-socialist alternative.14
• Communist Party: The Communists gained support by arguing that the depression confirmed their prediction of the inevitable collapse of capitalism, attracting voters from the working class who were disillusioned by the economic failure of the democratic system.12