Actually, parts of 2008 and early 2009 were a blueprint for how that sort of thing unfolds. The volatility is cranked way up and the highs of previous sessions are almost always penetrated before the market would sell off violently in the final hour. So basically, short and hold was a near impossible strategy unless you were willing to give back all of your open equity in the hope that the market would settle 2-3% lower, which it often did.
On the flipside, the current market simply drifts higher with almost no volatility (or very little intra-day volatility). More often than not, it's a gap opening that doesn't fill or it's a drift sideways until the final 30 minutes to hour where it's jammed higher.