Liam Donovan

# Posts

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Tales from Prediction Markets

Because mr co2 guy was clearly making a -EV bet that happened to pay off this time :)

Speculations Concerning the First Free-ish Prediction Market

FWIW FTX allows you to bet on its prediction markets on margin with a tokenized version of the S&P 500 as collateral, which accomplishes exactly what you want to accomplish here

The EMH is False - Specific Strong Evidence

markets that easily allow you to make tens of thousands of dollars with nearly no risk.

Back during November-January, FTX had a contract called TRUMPFEB that gave  ~risk free ~15% returns in 2 months, up to millions of dollars (by betting against Trump to be president in Feburary). Right now the FTX OLY2021 market comes pretty darn close -- you can bet hundreds of thousands of dollars on the Olympics happening at 76c. There is obviously the risk of the Olympics not happening, but I haven't seen a good case for that risk being under 10%, making this a fantastic trade in expectation.

Violating the EMH - Prediction Markets

Just commenting to say this is a great post and I'm surprised it hasn't gotten more engagement (maybe it's so good there's nothing else to say)

Exploiting Crypto Prediction Markets for Fun and Profit

The fees are always 2% of the transaction value; i.e. numShares*avgPrice. The trick I described lets you substitute (1-avgPrice) when that would be cheaper . I should've been much clearer about this initially; I forgot that most people here probably don't know the polymarket fee structure.

Exploiting Crypto Prediction Markets for Fun and Profit

You still pay fees, they're just lower. Most sharps on polymarket do indeed do this

Exploiting Crypto Prediction Markets for Fun and Profit

I don't know about Omen, but on Polymarket you can mostly avoid this issue by minting a complete set of shares and selling the cheaper side. In your example this would only cost you $0.0004 in fees to acquire shares at$0.98. The easiest way I know of to mint complete shares is to add and then immediately remove liquidity

Bet On Biden

But he's been a professional politics gambler for years now, which seems like much stronger evidence for evaluating his calibration than the results of one election cycle?

The Pyramid And The Garden

But that line has an infinitesimal chance of intersecting with any point as significant as the Great Pyramids? Scott's argument about Uganda and Tanzania seems wrong for the same reasons

Ongoing free money at PredictIt

I'm probably too late here but if anyone's wondering, PI will send you a 1099-MISC with $8.57 of income, and that's what you have to pay taxes on. (well, they only send the form if you make over$600, but that doesn't change your tax liability).

The \$85 you deposit definitely does not count as income, regardless of whether you itemize deductions. Regarding the discussion below, the IRS does not treat PI winnings as gambling income, but rather as 1099-MISC (other) income.

(source: have paid taxes on PredictIt winnings)