trading volume is a criteria used when making purchasing decisions, since stocks with low trading volume may be hard to get in or out of quickly if there are no buyers or sellers respectively. I do not know specifically though what the minimum requirements are for different brokerage houses. Performance criteria for a specific fund (with its manager's investment strategies) is spelled out in that specific fund's prospectus. There are a myriad of investment strategies for fund managers especially if they use quantitative analysis instead of or in addition to qualitative analysis.
So maybe go look at Fidelity or another company online and review the prospectus of aggressive growth funds to see the criteria they use for buy/sell/hold decisions. I think you'll be pretty hard pressed though to find any funds that purchase unaudited pink sheeted stocks that trade thinly.
Market Data 
Markets 
AI
