The recruiting class is led by four-star linebacker Demeioun Robinson.
Trader Jr. is a five-star lacrosse recruit and a three-star football recruit.
Revaz will battle for playing time with Chol Marial and Galin Smith.
Penn announced he would play at LSU.
Williams is the top-rated quarterback in the class of 2021.
The three-star product joins the Terps from nearby St. John's College High School.
The forward's decision leaves the Terps' frontcourt depth thin.
DeGennaro is the Terps' second wideout in their 2020 class so far.