For as long as I worked on the Street there have been those that have adhered to the summer rally theory. Supposedly stocks can do really well during the summer. Maybe it's wishful thinking but many believe that thin volume, while many traders are on vacation, can lead to higher prices. For my part, I really never bought this theory, but with summer officially beginning on June 21 I do believe that this year may feature a pop in stock prices during the hot days to come. Basically, this position is based on valuation analysis suggesting that many big name stocks are very moderately priced and should be commanding higher multiples. Will it happen? Who knows? Unexpected things happen that can influence the market negatively. However, on "fundamentals" I believe that on a short term basis stock prices with trend higher.