Certainly the proliferation of alternative data (online news sentiment, satellite imaginary, GPS location data, etc) has made finding those cheap harder to find

Certainly the proliferation of alternative data (online news sentiment, satellite imaginary, GPS location data, etc) has made finding those cheap harder to find because they are probably more fairly priced. Buffet has said that he switched his strategy from finding fair companies and a great price to great companies at a fair price, probably because of this increase of transparency. Also, there are fewer public companies today than in the past, due to consolidation or better liquidity in secondary (private) markets. If we ranked companies by P/E nowadays, and look at the cheapest stuff, it's often not worth buying. We're talking about the garbage companies that no longer can compete anymore. I think this is partially why value in underperforming. It's picking up all of this garbage that is actually fairly valued, and not cheap because people forgot about it. Funds like AQR do use value, but then often combine it with a factor that has a negative correlation with it, like momentum. Obviously you wouldn't want to combine value and growth (as they should have a close to -1 correlation, depending on how you define it), but adding a factor that has some negative correlation is very powerful. An example of using the combination of these two factors might work like this: I see a company that looks relatively cheap, but not cheap enough for a value strategy. I think find it has an upward momentum (the price is rising), though only moderately. Alone, neither of these signals would be strong enough for a buy. But together, I might infer that the company is turning itself around and things are going to get better.