Other hyponyms of step-up include
addition,
advance,
rise,
appreciation,
surge,
upsurge,
augmentation,
amplification,
enlargement,
expansion,
escalation,
maximation,
maximisation,
maximization,
exaggeration,
expansion,
accrual,
accruement,
accumulation,
inclusion,
aggrandisement,
aggrandizement,
elevation,
strengthening,
intensification,
intensification,
split,
split up,
stock split.