Hate to be the materialistic weasel of the bunch here.
Do what ya can to protect it. Prevent break ins, or from stealing the whole trailer.
Just remember, you only slow them down. Or they'll destroy it because they can't take it.
If they want it. they'll take it.
I've had a 16' flatbed trailer stolen with a hitch lock on it. They torched the lock and took the trailer. Trailer was never recovered.
A friend at the marina where we had our boat, had a boat and trailer with a removable tongue he'd throw in the truck when gone. Someone drove away with it anyway, right out of his driveway.
And remember this is a time, where more and more, people don't want to get involved. So expecting help from others to protect your property probably won't happen.
Best you can do is. Check around and get the best insurance available to cover the loss. So if a theft does happen, maybe it will be covered enough to replace it.