Have you noticed the number of high-profile investors (most notably George Soros + the Goldman Sachs team) calling for a market downturn? The right question to ask is why. In my opinion, they sold out earlier (in Soros' case, hedged with SPY puts) and are hoping to reenter at lower prices.
This morning, Janet Yellen is signaling an increase in interest rates. The DJIA promptly responded by rallying +120 points. So a rate hike was already priced in.
I still believe we're overdue for a sharp dive, but for the time being a combination of skepticism (record high cash positions reported by global funds, all the more remarkable as US indexes set new highs) + short bets has placed a 'floor' under the markets.
My best guess? The S&P500 (currently trading around 2184) will rise another 4-5% before we take a nosedive. Of course, it's only a guess and we may well spiral down before Labor Day!