Every thought that is a real thought has an effect on action. Since no action is guaranteed success, every thought that is a genuine thought runs a risk. The corollary is that if there is a thought that runs no risk, it’s not really a thought, it’s a pseudo thought. For example, I would argue that “everything in moderation” is a pseudo-thought because we have no independent standard of what counts as moderation other than our sense of how much to do something. So “everything in moderation” really means “don’t do something more or less than is appropriate” — in other words it doesn’t mean anything.
That said, there are some thoughts that are very low risk. The thought that the sun is going to come up tomorrow is one. Maybe it won’t but it probably will.
There are some thoughts that are such high risk I don’t know anybody who would think them. The thought that the way to live a noble life is to buy a jar of beans and sit on the floor counting and re-counting them is such a risky thought you’d have to be crazy to think it.
There are some thoughts that are very high risk, but might still be worth thinking. For example, the thought that the most worthwhile life is one of trying to help the poorest of the poor. It’s a high risk. If you go to a shanty town in a huge third world city and spend your life giving out anti-malaria medicine and that’s not a worthwhile life you have lost a lot. Possibly you have wasted your life.
On the other hand, if that is the most worthwhile may of your living your life then staying home, working a corporate job and putting money in the stock market is also a high-risk move. That could be wasting your life.
Trying not to run a risk is itself risky. Just as putting money in the bank seems safe but isn’t because of inflation, putting your thoughts into the bank of cliches seems safe but is actually risky.
If, as seems likely, you have only one life, you should think some risky thoughts.