The S&P 500 Index just posted its third straight winning week and is up 5.1% in the third quarter.
Traders are trying to decide how to respond to rate reductions during a time of economic growth.
Like nearly three decades ago, bonds and stocks are rallying ahead of a critical Fed meeting.
The S&P 500 soared, helped by gains in rate-sensitive tech stocks like Nvidia, Apple and Amazon.
The potential for a large swing comes as volatility across markets has been historically restrained.
Nearly a third of the index's constituents have hit a one-month low in the past month.
The options market is betting the S&P 500 Index will move 1.3% to 1.4% in either direction.
The Fed may hint at how much it may cut interest rates this year.
The profits of large tech companies are expected to slow dramatically.
The semiconductor industry is notoriously cyclical, with regular boom and bust cycles.