This has been a popular form of betting through Betfair for awhile, and it may be coming to the states at last. It has the potential of opening many different 'non-traditional' wagering options. Stay tuned! From northjersey.com:
N.J. may try new way to bet on horses to help tracks – NorthJersey.com
Imagine being able to bet on a horse race even while the horses are on the backstretch — or being able to wager on a photo finish while it's being reviewed.
Such options already exist in Europe, and some of them may be coming to New Jersey next year. State officials aren't quite ready to make the full leap, but facing the potential collapse of its horse racing industry, New Jersey is likely to become the first state to take a dramatic step in that direction.
The new form of betting is called "exchange wagering," which is appropriate, because the concept is reminiscent of the stock market — with many bettors acting like traders.
For the full article, go here: http://www.northjersey.com/news/105618958_N_J__may_try_new_way_to_bet_on_horses_to_help_tracks_.html