Barometer Stock

See bellwether stock.

It's any security which is thought to be the general standard, or gauge of industry performance. Sometimes this is because a particular stock thoroughly exemplifies industry trends, and other times (more commonly) it is because that particular security is large and relevant enough to have a deciding impact on the direction of its industry or sector.

As goes the barometer stock, so goes the sector.

Generally. JP Morgan Chase and Intel are thought of as barometer stocks for the finance and tech sectors, respectively. They survive in good weather or bad...but they get wet when it rains.