Risk free rate - 2, 5, 10 or 30 years US treasury

Which tenor is more suitable to be the risk-free rate - 2, 5, 10 or 30 years US treasury?

Thanks.

depends on the maturity of the cash flow you are discounting, it should be the same.

If we value CAPM, tenor should be as long as possible?

It should be the rate for your expected holding period.

Thanks Magician!

Magician should become a central banker

What makes you think I’m not already?

I don’t think that’s correct. If you’re choosing a riskfree rate to use in CAPM, you should choose a short-term t-bill rate.

Why?