My clues to buy the gap down were:
Gaps get filled
The rest of the 3D sector bounced, all green, VJET will be the laggard
LOTS of volume showing accumulation as it churned mid 3s
Overbought conditions led to a profit taking selloff combined with a short attack lead by articles and such saying VJET was way overvalued...which may be entirely true. But shorts have to cover, and the gap down open was their chance to do it.