5 Min Read LONDON (Reuters) - Wall Street is abuzz about stock market bubbles as surges in the share prices of some loss-making firms, red-hot public markets and amateur investors chasing stocks at frothy valuations spark fears of a pullback. FILE PHOTO: The Charging Bull or Wall Street Bull is pictured in the Manhattan borough of New York City, New York, U.S., January 16, 2019. REUTERS/Carlo Allegri/File Photo A flood of money supply, ultra-low or zero interest rates and COVID-19 vaccine rollouts have sparked a ‘buy everything’ rally, helping world stocks add a whopping $33 trillion in value from their lows of last March.