Hello and thanks so much for presenting a valid question related to DAG nodes! The 250K $DAG is collateral to be held in the designated node wallet (your wallet). You never risk loss of your collateral by allowing it to serve as node collateral on the network. I would say ultimately the biggest risk, for anyone using an online wallet even fiat based, is the persistent scammers attempting to gain access to your wallet. You can remove your node collateral at any time you so desire as it isn't LOCKED. Just remember that snapshots happen on each node wallet and if the balance drops below 250,000 quantity $DAG, you potentially lose your node (spot/network contribution) and certainly have affected your rewards and PRO score.