To run a risk is to act in a way that could go badly wrong, knowing that it could. You post the only copy and hope.
It takes of plus a gerund: run a risk of losing everything. Run is the old sense of exposing yourself to something, the same one behind run the gauntlet. Take a risk is the everyday twin and the two are close, but running one leans towards a danger you have accepted as the price of something else, where taking one leans towards a gamble you chose.
1phraserun a riskTo act in a way that could go badly wrong.
“You run a risk of losing the deposit if you sign now.”
run a risk is an exposure to danger.
Practised in Common Word Pairs