Actually, it's manipulation by a few traders who push it up and down according to their own schedule.
They lose control only when there is significant news, like an earnings report or upgrade.
Been like this for months now.
Last week, in spite of a falling market, it served their purpose to hold it in a narrow range.
Yesterday, they held it back while the rest of the market was climbing, and today, though the market is up yet again, they're driving it down a bit, probably to accumulate or cover a short position established in the past couple of days.