Enough of sellingIn a downtrend, prices fall because there is an excess of supply over demand. The lower prices go, the more attractive prices become to those waiting on the sidelines to buy the shares. At some level, demand that would have been slowly increasing will rise to the level where it matches supply. At this point, prices will stop falling. This is support.
Support can be a price level on the chart or a price zone. In any event, support is an area on a price chart that shows buyers’ willingness to buy. It is at this level that demand will usually overwhelm supply, causing the price decline to halt and reverse.