Only players who finished inside the top 100 of the 2018 Halloween Event leaderboard ever received this unique knife. There is no other way to get one now: it does not come from boxes, events or any shop, so the supply is fixed to those leaderboard spots. That is why traders keep an eye on it — it works as a trophy from a specific event rather than a regular drop. If you see Red Hallow in someone's inventory, it either belongs to an original top-100 finisher or passed through a trade.
Questions players ask
How much is Red Hallow worth?
There is no stable price: trophies rarely change hands and deals happen privately. The number on value lists is symbolic.
Can you still get Red Hallow?
No. It was awarded for a leaderboard place in an event and is not given out again.