Is a 40% decline possible for the market?

 Here is the long term chart for S&P 500. Clearly it is in a super bull run for over a decade. But it has been too much away from its trend line, which makes it vulnerable for a major correction at some point of time. However, even if it starts a 40% correction, it will still be in the bull market uptrend as long as it stays above the trend line. While I'm not saying this will definitely occur, it is not out of the possibility for a severe correction within the bull market. 

 

 

 

This is what I meant for the rotation for the past two days: a more pronounced decline for the high-flying NVDA vs the up moves by the lagging stock CSCO. While two days are not sufficient for a trend, it may just be the start of a major rotation in the next few weeks.