what is a trendline 
trendlines are easily recognizable lines that traders draw on charts to connect a series of prices together or show some data s best fit the resulting line is then used to give the trader a good idea of the direction in which an investment s value might move a trendline is a line drawn over pivot highs or under pivot lows to show the prevailing direction of price trendlines are a visual representation of support and resistance in any time frame they show direction and speed of price and also describe patterns during periods of price contraction investopedia hilary allison