The Ultimate Collector's Series, or UCS, is a LEGO subtheme of Star Wars introduced in 2000 and was meant to be more detailed and aimed at older builders. These Ultimate Collector's Series sets tend to be larger, and more expensive than typical sets.
2019 LEGO Sets
There were a number of events in 2019 that helped shaped the investment market for LEGO. Probably the most important event is that LEGO Star Wars celebrated its 20th anniversary. In addition, LEGO released new themes such as Hidden Side, Overwatch and a set based on the Netflix series Stranger Things. Sadly the Nexo Knights and Elves themes were discontinued in 2019.