We prove the local asymptotic normality for the full parameters of the normal inverse
Gaussian Lévy process X, when we observe high-frequency data
XΔn,X2Δn,...,XnΔn
with sampling mesh Δn → 0 and the terminal
sampling time nΔn → ∞. The
rate of convergence turns out to be (√nΔn, √nΔn, √n, √n) for the dominating parameter
(α,β,δ,μ), where α stands for the heaviness of the
tails, β the degree of skewness, δ the scale, and
μ the location. The essential feature in our study is that the suitably
normalized increments of X in small time is approximately
Cauchy-distributed, which specifically comes out in the form of the asymptotic Fisher
information matrix.