def METHOD_NAME(self, cmatrix: correlationEstimate):
    valid_assets = list(
        set(self.assets_with_data()).intersection(set(cmatrix.assets_with_data()))
    )
    weights_valid = self.subset(valid_assets)
    corr_valid = cmatrix.subset(valid_assets)
    weights_np = weights_valid.as_np()
    corr_np = corr_valid.as_np()
    variance = weights_np.dot(corr_np).dot(weights_np)
    risk = variance**0.5
    return risk