Compression hem (also called raw cut) means the shorts have no separate gripper material at the leg opening—instead, the fabric's own stretch and compression keep the hem in place, with a clean, raw-cut edge against your skin. This creates a sleek, seamless look with no gripper marks, which is why it's popular on premium and aero shorts.
The trade-off is that compression hems rely entirely on the fabric's grip, so they can slide up on some body types, especially during hot or sweaty rides when skin gets slick. They're best suited for riders with a leg shape that works well with compression, and for cooler conditions or shorter efforts like time trials where the clean aesthetic matters.
If you prioritize a refined look and don't mind potential adjustments during long, hot rides, raw-cut hems feel premium. But if your shorts tend to ride up already, you'll likely be happier with silicone dot or band grippers for more reliable hold.