I participated in SFI's "Double Auction Tournament" a couple of years ago, placing second. Computer programs participated in a stock market game, with individual buyers and sellers competing with each other to make profit from fictional tokens. The emphasis of the contest was on computer trading strategies, not on monetary systems or computer security. This new "token exchange" sounds like a continuation of the original contest in which there will be an opportunity to compete and refine strategies over a longer term. It will probably be run from a central server with minimal concern over security; these are economists interested in stock market systems, not computer security people. In the original contest, there was a prize pool of $10,000 divided among the 30 contestants, with no contestant winning more than about $500. It seems likely that they'll have a similar bankroll for this one, as an inducement for people to compete. -- Marc Ringuette (mnr@cs.cmu.edu)