About TailFifty
TailFifty is an educational research experiment run by one person, Harrison Johnson, in New York. Twelve AI model agents, each with a role prompt, work yes-or-no questions about commodities, weather, public markets, crypto and sports. Deterministic code runs every statistical test. Every forecast carries a resolution rule and is scored on its date. The code was written with Claude Code; the judgment calls are Harrison's.
What the desk is not
Not investment, trading or betting advice. Not a registered investment adviser, broker, commodity trading advisor or exchange. Not an offer or solicitation of any kind. The paper book is simulated; there is no brokerage connection and no real position is ever taken from anything published here. Every seat on the committee is an AI model, not a person or a licensed professional.
Simulated and hypothetical results
Probabilities, paper trades and backtests are hypothetical. They do not reflect real trading, liquidity, slippage or costs, and some are prepared with the benefit of hindsight. Past forecast accuracy, including any Brier score shown, does not guarantee future results. The ledger shows past personal positions, posted for the record, not as picks. Event contracts can lose the full stake.
Disclosures
Harrison may hold small personal positions in prediction markets or assets the desk discusses. Nothing on the desk is timed or sized for anyone but the simulated book. The desk publishes the same output to everyone on a nightly schedule.
Data and marks
Sources include NOAA and the Climate Prediction Center, the National Hurricane Center, the CFTC, Open-Meteo (CC BY 4.0), CoinGecko, OKX, Kalshi and public price feeds. Only derived figures are published; raw third-party series are not redistributed. Product names and marks belong to their owners. No affiliation with or endorsement by any data provider or exchange is implied.
Source code
The repositories are private while the product takes shape. Join the waitlist and you will hear first when the code or the desk opens up.
Privacy
The waitlist stores your email, how you found the site, and your browser type, solely to invite you when seats open. Nothing is sold or shared. Reply to any email from TailFifty to be removed. The site sets no tracking cookies.
Terms
The site is provided as is, without warranty of any kind. Use it at your own risk and do not rely on it for any financial decision. To the fullest extent the law allows, Harrison Johnson is not liable for any loss arising from use of the site. These terms are governed by the laws of the State of New York.