1) Doing very well 2) Getting better 3) On a winning streak 4) On an upward curve 5) On the increase 6) On the way 7) Rising 8) Shooting up Found on https://www.crosswordclues.com/clue/improving
Im·prov'ing adjective Tending to improve, beneficial; growing better. -- Im*prov'ing*ly , adverb Improving lease (Scots Law) , an extended lease to induce the tenant to make improvements on the premises. Found on http://www.encyclo.co.uk/webster/I/25