Rerating for a company with earnings simply means the PE ratio...

Rerating for a company with earnings simply means the PE ratio is being rated higher. As such the SP would be higher. It may or may not gap up depends on the rerating event. It could be gradually being bought up.

In speccies such ad AVB with no earning hence no PE ratio to speak of, reraring will probably based on the proven resource valuation. Although in speccies, a perceived value may push the SP higher than the actual value.

The talk of reraring is more valuable than the rerating itself for speccies since there is no PE guidance.