That is common when there is the possibility that the common stock could exceed a certain amount, in this case double the exercise price.
Really nothing to worry about since my plan is not to exercise them but trade them, and I can assure you I will be long gone from XELAW before it hits $24 - That would give the warrant a value of $12.50
I'd sell at more than half of that if need be........... I'm not greedy.