kailash D. rajput 

in finacial market ,we use this technique that claims to 
ability to forecast the future security price of share n 
product through the study of past market data its known as 
technical anlaysis

Technical analysis is a security analysis discipline for
forecasting the future direction of prices through the study
of past market data, primarily price and volume.Technicians
say that a market's price reflects all relevant information,
so their analysis looks more at "internals" than at
"externals" such as news events. Price action also tends to
repeat itself because investors collectively tend toward
patterned behavior – hence technicians' focus on
identifiable trends and conditions.