He means it's hard to make money by being a good judge of a company. In the old days you could look at new product introductions and predict better than the majority stockholders (pension funds and insurance companies) how they would affect revenue. They would buy after the next quarterly report showed higher earnings, and you could sell to them at a decent profit. Smart individuals who knew an industry could make decent money. That's no longer true, because HFTs are jumping in front of your transactions.