While technology companies dominated the large-cap index, the highest percentage of new entrants in Russell 3000 in 2020 belonged primarily to the Professional and Scientific.
On the other hand, not surprisingly (post COVID-19), there were five companies belonging to the Accommodation and Food Services industry that exited the Russell 3000, but none within that industry entered the Russell.
Companies exiting the Russell were more likely to have a legacy defined-benefit plan, leading to additional financial pressue on these bigger companies wih under-funded defined benefit plans (see this post).