Quote:
Originally Posted by mn_trader
BTW, at the horse track, where odds change all the time based on current action or if a horse drops out, you can cancel the bet up until the race starts.
I am not saying this is applicable to this situation, but to all those who thing it is unheard of to cancel a bet, it is actually quiet common in one area of the gambling world.
Theoretically, if we have liquid markets and clean numbers, if you don't like a bet, you should have no problem unwinding (or hedging) it so shortly after the bet is placed for a very small transaction fee.
The key difference with horse betting is that it's parimutuel. It's fair to allow betting and canceling at any point before the event because the odds are based on how much money is bet on each horse at race time, not when you place the bet. If information comes out before the race, all bettors are free to change their bets accordingly.
For a bet like this, which is more like a sports bet, your odds are fixed when you make the bet. That's why it's unfair to allow canceling a bet. You could just let the bet ride when favorable information comes out, and cancel it if you get unfavorable info. The odds you get on the bet are based on an estimation of future events. Whatever happens before the event is part of the risk.
All these analogies to forms of betting where prior knowledge doesn't affect the EV are absurd.