Most quality stocks were lower in price 6-30-06 than they are today. Starting about 7-06 the FOMC has taken a stance of not increasing or lowering short term interest rates. This has had a very positive effect on the stock market. Investors have viewed this as an opportunity to invest in stocks and they have been very bullish. The DOW is approaching 12500 which is unprecedented.
The bears in the market have taken some profit and are now waiting on the sidelines to determine if there is going to be a market correction. No one knows if the bulls are through buying.