Talk about keeping it 100. The Nasdaq 100 index, which largely tracks large-cap tech stocks, rose to a new high on Thursday. What's striking is just how un-unusual this now is. In fact, as of Thursday's close, the index has hit record highs in 9 of the past 11 sessions. The Nasdaq 100 also has logged gains in 24 of the past 30 sessions, for an incredible...