In the CAPM theory Beta of asset $i$ are estimated in this way:
$ \beta_i = \frac{\sigma_{im}}{\sigma^2_m} $ where $\sigma_{im} = \rho_{im} \sigma_i \sigma_m$
But all these data are historical data. So, I'm wondering what if I use
$\sigma^2_m$ <- Implied volatility of SP500 (VIX)
$\sigma_{im}$ <- implied volatility for the asset $i$ using the at-the-money call option with a 1-month maturity.
- $\rho_{im}$ will be statistically estimated.
This way is a better estimation of the $\beta_{i}$ for the next month?