You simply cannot geld him after spending $150k and his bro starring but gelded.
Do you agree?

There is every chance that Waikiki Beach's full bro could earn more than his purchase price in first season at stud so if it came to a decision between having to geld him to race him or keep him as an entire, I would be tempted to send him to stud and let his bro do the talking

http://www.harnessbred.com/APG/MELB/CATALOGUE/#page/348