The signature is a "4" with a small loop at the top and a series of rounded zig-zags. Just out of curiosity, I grabbed a Sharpie from my desk and practiced those zig-zags for about 5 minutes and it's a really easy motion to do with your hand. A 10-year old could forge that. Try it.
My advice with Trump is stick to his older, more legible signature. Buy inscriptions.