Goldman says tech stock 'up crash' is sign of even more gains to come

Stocks are rallying so fast it's creating a volatility dynamic that's only been seen four times in history — and equity prices kept climbing following each instance. Implied volatility in the S&P 500 and Nasdaq-100 has held firm despite record after record, with the VIX little changed since slipping below 18 in mid-April despite the S&P 500 up 7% since. …