Within the stock market, the term overweight can be used in two different contexts.[1]
A rating of a stock by a financial analyst as having better value for money than other stocks. The other possible ratings are "underweight" and "equal weight", to indicate a particular stock's attractiveness.[2]
A judgement of an investment portfolio that it holds proportionately more than the benchmark weight of a certain asset (a share, bond, industry/sector, country, currency, or asset class, etc.).