We develop two new estimators for a general class of stationary GARCH models with possibly
heavy tailed asymmetrically distributed errors, covering processes with symmetric and asymmet-
ric feedback like GARCH, Asymmetric GARCH, VGARCH and Quadratic GARCH. The first
estimator arises from negligibly trimming QML criterion equations according to error extremes.
The second imbeds negligibly transformed errors into QML score equations for a Method of
Moments estimator. In this case, we exploit a sub-class of redescending transforms that includes
tail-trimming and functions popular in the robust estimation literature, and we re-center the
transformed errors to minimize small sample bias. The negligible transforms allow both identifi-
cation of the true parameter and asymptotic normality. We present a consistent estimator of the
covariance matrix that permits classic inference without knowledge of the rate of convergence.
A simulation study shows both of our estimators trump existing ones for sharpness and approx-
imate normality including QML, Log-LAD, and two types of non-Gaussian QML (Laplace and
Power-Law). Finally, we apply the tail-trimmed QML estimator to financial data.