The bull markets or the bear markets have a tendency to give different types of gaps it is a situation where no trading has been taking place, which can be clearly seen, on the charts.
Breakaway gaps: - On the completion of a price pattern usually a gap occurs and generally give signals on the beginning of the significant market move. These gaps occur on heavy volumes. It is confusion among investors and they think that gaps have to be filled. Breakaway gaps generally dont fill soon.

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Runaway gaps: - After the move has been underway for a while, somewhere around the middle of the move, prices will leap forward to form a second type of gap (or a series of gaps) called the runway gap. This type of gap reveals a situation where the market is moving effortlessly on moderate volume.

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Common gaps: - A gap that usually occurs in very thinly traded markets or in the middle of horizontal trading ranges. It is more a symptom of a lack of interest than anything else.

 Exhaustion gap: - It appears near the end of a market move. When markets are in the strong uptrend, they give gaps, which can be breakaway, runway, or exhaustion gaps. The exhaustion gaps are seen at the end of the bulletin, when near the fag end the stock market seems to be exhausted and suddenly they take a last jump up with a gap and after that stays sideways and then start falling.

Closing the gap : - It refers to pulling the prices back to the levels at which the gap was formed. For example let us take a stock, which in the way of its upward movement closed a week at Rs54 and in the week following it opened at Rs55.5 and moved further to Rs68 without coming even at Rs56. Here a gap of Rs1.5 is created. The gap will be considered as closed when the price of stock comes down to the rate at which the gap was created (Rs54). Normally when stocks begin their journey from consolidation phase, they move with a gap, which is not easy to be filled.

This is an order which remains in the system till it is not cancelled, stop loss or executed.

The Head and Shoulder pattern indicates the arrival of a reversal pattern. It appears as if three mountains are standing out of which the middle one is the tallest. Formation of a head and shoulders pattern goes through the following phases:
1st A strong rally along with heavy volumes takes the prices to a high level, this rally is followed by a small recession which has lesser number of volumes. It forms the Left shoulder of Head and shoulder pattern.

2nd Again high volume rally starts which makes a top higher than the earlier one, after that another small recession with low volumes begins which takes the prices near to the bottom level of the earlier recession. This low is usually near to the low level made earlier and it is lower then the earlier top also. It forms the Head of Head and shoulder pattern.

3rd The third rally starts from here, this time it has less volume than the earlier rallies. It fails to meet the head and ends at a lower level. It forms the Right shoulder of Head and shoulder pattern. One more decline starts after completion of this formation.

4th If downward recession takes the prices below the Neckline (the line formed by joining the bottoms of head of H & S pattern) by around 3%, a breakout in the prices follows.

Above definition is what most of the books and theoreticians try to find but in reality one hardly comes along such a fine head and shoulder. So a variation of the above can always be there. Best is if you find the head and shoulder in many stocks, that means market will go down. If you just find one stock or index with head and shoulder formation but do not find other bearish formations elsewhere then be careful.

Hedging is a term which is something like spread where you buy a strong stock and sell a weak future with the result that if the market goes up then you earn more in the strong stock as chances of the weak stock going up will be less.  If the market falls, then weak stock will fall more as compared to the strong stock.