3 ms·

Looks to me like the time of the day.

• gahahaha 14y ago
  You are correct. Felix Salmon comments: http://blogs.reuters.com/felix-salmon/2012/08/06/chart-of-the-day-hft-edition/ http://blogs.reuters.com/felix-salmon/2012/08/06/chart-of-th... > in 2008, a pattern starts to emerge: a big spike right at the close, at 4pm, which is soon mirrored by another spike at the open. This is the era of traders going off to play golf in the middle of the day, because nothing interesting happens except at the beginning and the end of the trading day. But it doesn’t last long.
• rgarcia 14y ago
  That's the x-axis.