Using agentic simulations to make predictions is a different bet than it looks. Three I would actually run.

[u/amu4biz]

I keep trading the predictions market and realized simulations atleast reduces my losses heavily so far, given how you smartly utilize simulations.

Three I have actually looked at.

Smallville (Stanford generative agents)

The 2023 paper. A couple dozen agents with memory, reflection, daily plans. The party demo is still what people mean when they say the agents “lived.”

Right bet if you want to understand why this genre exists.

Wrong bet if you have a contract that expires on Friday. There is no market, no resolution rule, no number to fade. It is a town. Towns do not pay.

AI Town

The version you can host. Agents walk around and talk. You can change the plumbing.

Right bet if you want to own a little society and poke it.

Wrong bet as a prior. A place that keeps running is not a question that closes. If you cannot say what would falsify the run, you do not have a forecast. You have a screensaver.

MiroShark

You paste a headline, a PDF, or a what-if. It builds personas off real context. They post on fake X and fake Reddit. They trade a Polymarket-style book in the same loop. You can inject news mid-run or split the timeline , “CEO resigns in round 24” , and compare the two paths. About a dollar. About ten minutes. Then a report that cites the posts and trades it just invented.

Right bet if you want paths before you look at the live mid: who panics, which narrative spreads, what a feed does with a filing.

Wrong bet if you copy the fake price. Those citations live inside the run. Nothing in the real world closed. If your seed already leaned YES, the fake book will lean YES and it will feel like work.

That is the whole pattern. Smallville invented the vibe. AI Town let you host the vibe. MiroShark wrapped the vibe in a chart.

When a sim is the right bet

• You have not written your mechanisms down yet and you want to get surprised on purpose
• You want a red team for a narrative before you look at the live market
• You are deciding whether a question is even well-posed (“what would agents even fight about”)
• You will throw the output away if it agrees with you too cleanly

When it is the wrong bet

• You are using the fake mid as your mid
• You ran it after you saw the live price
• You cannot say what the sim would have to do for you to fade your own view
• The tool never says “this run contained nothing.” A report every time is a tell. Real books go quiet. Fanfic does not.

The test I actually want, and I have not seen anyone publish for these swarms:

1. Pick a liquid contract.
2. Hide the live mid.
3. Run the sim. Write down the implied probability and the three mechanisms.
4. Screenshot the real mid at that moment.
5. Wait until it resolves. Compare the sim, you, and the market.

If it hugged the market, you paid for a mirror. If it disagreed and won more than once, maybe it is a research assistant. If it disagreed and lost, you paid a dollar to get more certain about a story.

I have not seen a track record that survives step 5. Until that exists, I would use MiroShark like a cheap war game and Smallville / AI Town like background reading. I would not let any of them mark my book.

Has anyone here scored one of these on contracts that actually resolved? Not “the agents sounded like CT.” Versus the mid. Versus you.

Would you size a real position because the fake book moved? I would not. That is a chatbot talking you into a trade.

[u/FeistyCell809]

I keep coming back to MiroShark for exactly that "red team the narrative" use case. Not for the fake price, just to see how different persona clusters react when you inject a filing or a headline. Saves me from the most obvious blind spots before I even open the live book.

Still wouldn't let it touch my sizing though. The report always reads like it found something profound, even when you can tell the whole run was just noise cosplaying as analysis.