Key Points Amazon's portfolio position is significant for Ackman, but it's not his largest one. Uber’s combination of scale, management quality, and undervaluation has been the draw. Ackman calls it “extremely rare” in large caps, and investors can learn key some lessons. 10 stocks we like better than Uber Technologies › When billionaire investor Bill Ackman makes a move, Wall Street pays attention. The founder of Pershing Square has built his reputation on high-conviction, concentrated bets -- o ...