Wall Street's biggest bubble may be starting to unwind

Concerns are growing that one of Wall Street's most crowded market themes may be entering an unwind after an extended period of strong valuations and investor positioning.
A genuine bubble reversal would typically involve weakening momentum, declining valuations, deteriorating breadth and investors reducing exposure to previously crowded trades.
Whether the move develops into a sustained repricing or proves to be a temporary correction will depend on earnings, liquidity, interest rates and underlying demand.