After the Asian financial crisis in 1997, Buffett was concerned about the high market valuations and began to significantly reduce his stock holdings.
By the end of 1997, Buffett's stock position was 76%;
By the end of 1999, Buffett's stock position was only 37%;
So Buffett actually missed the sharp rise of the internet bubble in 2000, but he did not chase the rise, thus avoiding the burst of the internet bubble in 2000.
Starting at the end of 2005, Buffett began to gradually reduce his cash ratio.
As shown in the chart below, Buffett's bottom-fishing was a bit early, but Buffett's bottom-fishing is a long-term process and was not done all at once.
Until just before the outbreak of the subprime mortgage crisis in 2008, Buffett still had a high proportion of cash, and it was only when the subprime mortgage crisis broke out in 2008 that Buffett fully deployed his cash to bottom-fish at bargain prices.