ˈtipstə(r) noun
( -s )
Etymology: tip (IX) + -ster
: one who gives or sells tips or private information especially for gambling, stock speculation, or news writing
many touts and tipsters prepared to sell inside information — Dennis Craig
is best known as a stock market tipster — Martin Gardner
was the first editor to employ secret tipsters — W.A.Swanberg
police are often informed of crimes by tipsters