A positive earnings report from Analog Devices (ADI) ignited the semiconductor sector which has been a laggard for a while. These are the kind of episodic pivots worth tracking for long term investor.
The earning report from ADI and forward guidance brought in new piece of information which was immediately acted upon by market participants. Number of stocks in the sector reacted to the news immediately. Similarly few weeks ago a news from one auto component maker triggered a group move. Same is true of solar stocks where a news in mid January triggered a rally in the group and Trina Solar TSL, doubled since then.
Many times a news from one stock in the industry kicks off a multi month or multi year rally in the industry group. Often the stock which makes the announcement may or may not be the best buy on such news but other stocks which reacts to the news if they are already in rally mode or have better earnings take on leadership.