Yoonew is a site that implements a full-blown stock market for sports tickets. The site employs Lightstreamer to implement real-time streaming of the market data.

From their “How it works” page:
Yoonew is an open market that gives true fans the opportunity to lock in ticket prices to some of the most sought-after events in the world. Buying Fantasy Seats for your favorite teams allows you to guarantee yourself a ticket to the big game if your team makes it. yoonew is the only place in the world where you can score tickets at prices BELOW face value.
Suppose you’re a die hard Giants fan and want to go to Super Bowl XLII next year. However, you only want to go if the Giants make it and you can’t afford to spend $2,000+ per ticket. Instead of buying a ticket, you can buy a Fantasy Seat for the Giants in Super Bowl XLII. If you bought 2 Fantasy Seats for $200* a piece and the Giants reach the Super Bowl, you just scored a pair of super bowl tickets and saved $3,600! If the Giants don’t make it to the Super Bowl, however, your Fantasy Seats cannot be redeemed for tickets and you lose $400. At yoonew, you only pay ONCE. There are no additional payments or hidden fees.