Show HN: Zentrade.io – Bitcoin Prediction Markets

Re:Show HN: Zentrade.io – Bitcoin Prediction Markets by yummyfajitas on Friday March 07, 2014 @11:47AM (#7361230)

So this has the same flaw that Predictious has. It's building a BTC bank in addition to a prediction market.

That's the easiest thing to build, coming from a world of traditional fiat money banking. But BTC enables something superior - 2of3 transactions between betters. We create a 3 way transaction - Long says "I want the money". Short says "I want the money". When the bet is concluded the arbitrator says "Long won, give me 1%."

The arbitrator can never go insolvent - in fact, the arbitrator never needs to hold a single bitcoin.

[ Parent | on HN ]

Re:Show HN: Zentrade.io – Bitcoin Prediction Markets by Anderkent on Friday March 07, 2014 @12:31PM (#7361499)

You should check out https://github.com/psztorc/Truthcoin , which builds up on that idea to design a fully decentralized prediction market.

[ Parent | on HN ]

Re:Show HN: Zentrade.io – Bitcoin Prediction Markets by gwern on Friday March 07, 2014 @12:38PM (#7361551)

Or even better than multisig, on-blockchain transactions and Truthcoin: http://www.reddit.com/r/Bitcoin/comments/1ycjdi/whitepaper_d...

[ Parent | on HN ]

Re:Show HN: Zentrade.io – Bitcoin Prediction Markets by brador on Friday March 07, 2014 @12:12PM (#7361386)

What if the loser refuses to pay? How does the arbitrator get the coins without holding coins?

[ Parent | on HN ]

Re:Show HN: Zentrade.io – Bitcoin Prediction Markets by dispense on Friday March 07, 2014 @12:16PM (#7361410)

There is no such thing. In a 2 out of 3 transaction, 2 out of 3 parties have to agree for the transaction to happen. Thus, if the winner agrees and the arbitrator also agrees, the transactions is conducted. It's a cryptographically secure agreement.

[ Parent | on HN ]

Re:Show HN: Zentrade.io – Bitcoin Prediction Markets by brador on Friday March 07, 2014 @12:45PM (#7361598)

What if the arbitrator is colluding with the loser?

[ Parent | on HN ]

Re:Show HN: Zentrade.io – Bitcoin Prediction Markets by yummyfajitas on Friday March 07, 2014 @12:56PM (#7361675)

This problem is not solved via 2of3 transactions.

It can be partially mitigated by requiring multiple arbitrators (e.g. a 4/5 transaction with 3 hopefluly independent arbitrators).

[ Parent | on HN ]

Re:Show HN: Zentrade.io – Bitcoin Prediction Markets by dllthomas on Sunday March 09, 2014 @11:34AM (#7368675)

Unfortunately, there's no really good way of establishing that two pseudonyms are not held by the same person, in a decentralized system. Doubly so when legal enforcement isn't available. Of course abuse is harder the more arbitrators you incorporate, but expense and difficulty are higher as well.

[ Parent | on HN ]

Re:Show HN: Zentrade.io – Bitcoin Prediction Markets by dispense on Friday March 07, 2014 @01:34PM (#7361859)

That's a human problem, not a Bitcoin problem.

[ Parent | on HN ]