Bellwether trials are the first trials in a mass tort case. Cases are selected for trial that are thought to be representative of a particular issue in other cases in the class action. While the results of the trial are not binding on anyone other than the parties to the trial, the results are considered to be instructive on the value of the cases.
Why are they called “bellwether”? It is a good question. I never had any idea. In fact, for the first few years of my career I spelled it as “bellweather” trials. No one every corrected me. But apparently the genesis of the use of the word bellwether comes from belling a wether, which is a male sheep, who is elected to lead a group of sheep. The farmer would determine whether the wether was a good choice for the bell if the flock seemed to trust the sheep who had the bell. How this made its way in the MDL mass tort lexicon is anyone’s guess.