A self-directed investor bases stock purchase decisions on internet recommendations and stock tips, believing this...

The availability bias occurs when investors rely on easily available or recent information rather than a thorough analysis. In this case, the investor bases decisions on internet recommendations and stock tips, believing they are accurate, instead of analyzing fundamentals. This clearly matches availability bias.

Endowment bias applies when investors overvalue what they already own.

Representativeness bias applies when investors judge outcomes by stereotypes or past patterns.

Overconfidence refers to excessive faith in one’s own knowledge.

Thus, the behavioural bias here is Availability .