Falling stock prices are really a reflection of real-world problems - while it obviously feels in the US like everything is fine (judging from the many comments saying this here on this thread), everything is not fine, companies looking at their P/L and laying off staff are not fine, and the Fed is deliberately going to cause a recession and cause unemployment to stop inflation, which is a very brutal and indirect tool to do so.
The Jeremy Grantham interview you cite to for him "correctly" calling a bubble in 2021 was posted on May 28, 2021. S&P was at $420.04. S&P closed today at $395.52. The S&P continued to climb from May 28, 2021 until January 2022.
I would not label this "correctly" calling a bubble when he is off by over 6 months and equities remain within 10% of when he gave his interview.
The peak came after he spoke, in late 2021, and it’s not over yet, bear markets often have rallies. The nasdaq in comparison to s&p has larger losses from peak as it was the epicentre of the bubble this time, hence the layoffs there, but every sector is going to suffer.
He called this correctly in 2021, before it burst: https://www.livewiremarkets.com/wires/grantham-this-is-a-bub...
He feels there is still farther to fall (and I agree with him there): https://www.msn.com/en-us/money/markets/prepare-for-an-epic-...
Falling stock prices are really a reflection of real-world problems - while it obviously feels in the US like everything is fine (judging from the many comments saying this here on this thread), everything is not fine, companies looking at their P/L and laying off staff are not fine, and the Fed is deliberately going to cause a recession and cause unemployment to stop inflation, which is a very brutal and indirect tool to do so.
This will not be a soft landing.