Although Grace Life-tech Holdings' revenue has slumped, its P/S ratio stays high amidst investor expectations of future outperformance. Yet, without prospective business improvement, the sentiment fueling these prices is seen as untenable considering the company's lacklustre revenue growth.

Grace Life-tech Holdings' P/S is still higher than most industry peers despite share price weakness. However, the continuous decline in revenues coupled with a high P/S ratio could pose risks for shareholders and potential investors. There's a possibility of future disappointments if business turnaround expectations aren't met.