The Blood-Horse magazine has published an article based on a study from the U.K.
“For all but a very few mega owner-breeders—whose aim is to create stallion prospects and for whom this is very much a business—having one or more horses in training is a leisure pursuit, something to take the mind away from the day-to-day concerns of work, health, and family. As such, there is a line of thinking that you should not really expect a return on your leisure investments any more than if you take up golf or sailing, or hill walking.
But the reality is that racing is a professional sport which supports a whole industry and has prize money to match, most of which goes to the owner…” Read the findings here