brute force working the ladder, basically the ladder is created by the largest quantity on both buy/sell side. Any large party in after hours can control the ladder, this is done to work their own existing orders to sell at a higher average price and price tics down over a 8 hr period.
basically whats happening is the macro backdrop is being used to entrain a significant amount of shorts as the price action decays.
this entrainment will catch the less nimble offguard, windows of lack of news can lead to significant short covering rallies, and eventually new highs as stimulative effects from FED are rationalized to be turning the economy around next year.
the bigboys need to suck in shorts, its an opportunity that can't be passed up secondary to multiyear spans the macro backdrops are engineered in.