How to conduct an IPO pool
With the upcoming IPO here at Shutterfly, I naturally wanted a way to create a bit of a prediction market around it(some would call that gambling, but euphemisms are more fun). I’m most interested in how to set up reasonable market to predict the end of day price.
It’s obvious that a simple “every entry is $5, winner take all, closest to the number” is a terrible terrible idea. If you don’t understand why, think about what happens when I pick a number and then immediately get straddled by two other people picking numbers 1 cent above and below me. You could add minimum spacing increments(which is what we did with $.05 increments), but that only solves a part of the problem.
So what’s a better way? I thought of doing an auction market on every $1 increment in pricing. In summary, it’d be “bid on whether price will be $11-12, $12-13, $13-14, … every winner for each range has to pay up, and the correct price range takes it all” . It’s a bit more work, but seems a lot more fair.
I think that is pretty good. But I’m not sure if that’s efficient enough. Choosing the size of the ranges might be a bit tricky. But you can make ranges flexible by saying that any range can be subdivided by its current winner into two equal, half priced segments. And any current winner of two adjacent bids can consolidate the two ranges into one range as long as its new price is at least the sum of the individual prices. This is all nice, but the whole thing is still pretty complex. Maybe I’ll try this out for my next IPO.
It’d be good if there were a scheme which didn’t require individuals to track the whole market. If someone knows of a simple scheme which was just “I’ll buy in for $X and make a prediction of $Y” where the early predictors don’t get obviously and massively screwed tell me.
