In 2012, few people here assumed that the market in SD would rise 80-100% (nominal) from bottom by 2016.
In 2007, few people assumed that prices would fall 40-50% from peak.
All it would take for the market to fall a lot is for the market to fall a little. Falling prices = loss of confidence = more people selling = supply >> demand.
The reason inventory is low right now is that owners are holding hoping for even higher prices — if prices fall a little or even flatten, this goes away.