Donald Trump winning the US presidency is considered one of the top 10 risks facing the world, according to the Economist Intelligence Unit.
The research firm warns he could disrupt the global economy and heighten political and security risks in the US.
However, it does not expect Mr Trump to defeat Hillary Clinton who it sees as “his most likely Democratic contender”.
He is rated as riskier than Britain leaving the European Union or an armed clash in the South China Sea.
China encountering a “hard landing” or sharp economic slowdown and Russia’s interventions in Ukraine and Syria preceding a new “cold war” are among the events seen as more dangerous.
“Thus far Mr Trump has given very few details of his policies – and these tend to be prone to constant revision,” the EIU said in its global risk assessment, which looks at impact and probability.
The EIU ranking uses a scale of one to 25, with Mr Trump garnering a rating of 12, the same level of risk as “the rising threat of jihadi terrorism destabilising the global economy”.