The S&P 500 hit yet another record high on Thursday, closing at 5,241. That's a stunning rise of 27% in less than five months.

The big picture: The rise in the stock market coincides with a significant rise in expectations for GDP growth in 2024.

• Back in August, analysts expected just 0.6% GDP growth this year. Now, they're forecasting 2% growth.
• Federal Reserve officials are slightly more bullish still, with a 2.1% median forecast.