In the last 4 years there have been many financial crisis. The US was obviously the biggest one. Then we had trouble in Europe, Dubai, Iceland, Spain, Italy, Greece, and now Cyprus. The market has taken all those events in it tide and is still up and now approaching all time high.
Each event creates the feeling and echo chamber of big calamity, but nothing major has happened and life goes on. The economy keeps rebounding and the Fed is proactive.
That is the backdrop to the market. The breadth is a proxy for large speculators buying and selling. If they are aggressively buying we get series of 500 plus days, same way if they want to get out aggressively, it is reflected in bearish breadth numbers of 300 plus.
When there is slow and steady buying it is reflected in the kind of breadth we are getting currently. A grinding higher move. Characterized by creeping higher moves without big explosive moves on individual stocks.
There is a constant bid in the market and on every dip it shows up intraday or next day. This can continue as long as the pattern is not broken.
When you see 300 plus day to downside is when to get excited.