$SOX now and at past Major Bottoms showing the 1998 bottom, the 2002 bottom and the 2009 bottom. Bottoms can form quickly but usually they do not. In addition the low on a bottom is often tested months later:
I am showing the 2002 bottom in October on a daily chart of the DJIA and its retest 5 months later. Keep in mind the importance of volume. A major market bottom will form after selling has exhausted starting with a higher volume up day than the previous days selling. It's generally a 90% upside day:
Showing the last 3 years here on a similar daily chart. This was the highly elusive V major bottom in 2009. They just don't happen often: