Michael Burry suggests the current market ratio of 5:1 is unsustainable and dangerous, implying a significant downturn similar to a parabola snapping back.
"parabolas don't resolve sideways or basically to some things up he's just saying that five to one is not a sign of an efficient market where one investor buys a stock that the other sells this type of increase within the market is extremely dangerous because it could just as easily reverse or go up another 20 times but parabolas don't just level out they snap back to where they came from and in this case he implies it's going down"