Function eq_bailsman::rate::borrower_volatility

pub fn borrower_volatility(
    prices: &Vec<FixedI64>, 
    positive_balances: &Vec<FixedI64>, 
    covariance_matrix: &Vec<Vec<FixedI64>>
) -> Result<FixedI64, InterestRateError>

Calculates volatility for positive_balances - given set of collateral values