It always means that "not all active valuation algos could produce results"
This means one of two things:
1. (most common): The company is not profitable. Earning Per Share is less than 0. Because some valuation formulas need a positive EPS, these valuation formulas will show a "-" instead of data. And because not all valuation formulas could produce a result, the stock is marked with red brackets. Same for Free Cash Flow. A negative Free Cash Flow means company is not profitable, Discounted Cash Flow valuation formula cannot calculate a score.
2. (less common): The company did not publish EPS or other data needed for the valuation algo, a such, score for the given valuation cannot be calculated.
Bottom line in most cases: stay away from such stocks/companies, they are unprofitable and a such they are speculative.