There is an 800 pound gorilla in the pool business called Pool Corp (symbol POOL) who is in the business of supplying inground pool builders with the vast majority of the things they buy. They are the world’s largest such supplier. So when Pool Corp speaks, all of Indiana’s inground pool builders listen. Indiana Inground Pool Market. I am hearing some good things about the strength of the in ground pool market both nationally and in Central Indiana. I am also finding people are in the buying mode.