Paper trading a prediction market means placing a trade with no money behind it and scoring it as if it were real. Rivo, the prediction market terminal, runs paper mode on Kalshi, Polymarket, Polymarket US and Gemini: a paper order fills against the venue's live order book, pays the venue's own taker fee and settles when the real market settles. You place one by hand from any order ticket or let a bot record them for you.
Our take: a paper trade is only as good as its fill. A practice trade at the last traded price flatters every strategy. A practice trade against the real book, with the real fee, tells you what you would have paid.
Why does paper trading matter more in prediction markets than in stocks?
A stock simulator can assume you bought at the quoted price and be close enough. Three things make that assumption wrong on a prediction market.
The books are thin. A popular stock shows thousands of shares at the best price. Many prediction markets show a few dozen to a few hundred contracts there. A $500 order can takes three or four price levels, and your average fill ends up a cent or two worse than the price on the screen. On a contract worth 30 cents, one cent is more than 3% of your stake.
The fee changes with the price. Kalshi, Polymarket US and Gemini charge a taker fee shaped like coefficient x contracts x price x (1 - price). The fee peaks at 50 cents and shrinks toward the edges. Here is Kalshi's standard 0.07 rate on 100 contracts:
The dollar fee is the same at 20 and 80 cents. As a share of what you put in, it is four times bigger at 20. A longshot strategy pays far more of its stake in fees than a favorite strategy does, and a simulator with no fee hides that completely.
Settlement is all or nothing. A contract pays $1 or $0. A stock position that goes against you is down a few percent. A prediction market position that goes against you is down 100%. A 60% win rate makes money at 50 cents and loses money at 70 cents, so the price you paid decides whether a winning record is a profitable one. Paper trading at real prices is how you find out which kind of record you have.
How does paper mode work on Rivo?
Paper is a mode, not a separate product. Anything you do live on Rivo you can do on paper, by hand or by bot, on every venue the terminal covers.
How do you place a paper trade by hand?
- Open a market in the terminal.
- Open the order ticket on the side you want.
- Switch the ticket from Live to Paper.
- Enter dollars or contracts. The ticket shows the average fill, the fee, the total and the payout.
- Place the order.
Every ticket opens in Live. You choose Paper each time, and the ticket never remembers the choice, so a ticket cannot come up in Paper by surprise or in Live by habit.
The paper ticket follows five rules on every venue:
- The order walks the live book. A buy takes the lowest ask first, then the next level, until the size is filled.
- The venue's taker fee is part of the cost. The ticket uses each venue's own formula and rounding.
- Only what fills now counts. If the book fills 150 of your 400 contracts, the paper trade is 150.
- Nothing rests. A paper limit order trades what crosses on arrival and drops the remainder.
- A sell closes what you bought. You cannot open a short on paper. A sell reduces a position you placed by hand.
The paper ticket and the real ticket run the same pricing function. A paper order shows the numbers a live order would show at the same moment.
What does a paper fill use on each venue?
C is contracts and P is the price in dollars. Polymarket and Polymarket US are separate venues with separate books, accounts and fees. A paper trade on one never borrows a price from the other.
A worked example: $100 of Yes against a real book
One order, $100 of Yes on a market with Kalshi's standard fee. The asks are 80 contracts at 42 cents, 120 at 43 cents and 300 at 44 cents.
The naive version overstates the winning profit by 11% and understates the win rate you need by two and a half points. Over a hundred trades, that gap is the difference between a strategy that works and one that only looked like it. The full walk through this order, level by level, is on the Kalshi paper trading page.
Where do you see your paper trades?
Open Portfolio and switch from Live to Paper. The Paper side shows:
- Open holdings, marked against the current price on their venue.
- Settled holdings, paid at $1 or $0 on the real result.
- The source of each holding: placed by hand or recorded by a bot.
- Hand-placed sales, each with realized profit at your average cost.
Paper mode has no cash balance. Nothing stops you placing a $50,000 paper order, so the discipline is yours: trade on paper at the size you plan to trade live. The book fills $50 and $5,000 at different prices, and a record at the wrong size answers a question you did not ask.
What does each kind of paper bot record?
A bot is a trigger, a size and a mode. Rivo has three triggers, and each records its paper trades a little differently. Read this table before you compare one bot's record with another's.
Trader bots apply your filters, your sizing and your pause switch and nothing else. The record reads as the trader's results at your size. Size with a fixed dollar amount or a percentage of each of their trades with a dollar ceiling, and the builder shows the trader's typical trade so you know what the percentage comes to.
Signal bots start from a backtest. The builder scores your signal on settled markets, splits the window into a training part and a validation part and shows whether the result holds. The paper bot then records every new match. The method is on the backtesting page.
Market bots buy when a price drops or jumps by a number of points, or crosses a level, and sell at a profit target or a stop. A market bot can follow a repeating series, such as the 15 minute crypto markets, and move to the market trading now each time one settles. Its own record is its test.
Build any of the three in the bot builder. The overview is on the prediction market trading bot page.
What should you read in a paper record?
- Settled trades first. Open positions are marked at a current price. Settled ones are facts. A record with 6 settled trades and 40 open ones has not been scored yet.
- Win rate against the price paid. A 60% win rate at an average entry of 70 cents loses money. Compare the win rate with the average entry price, never with 50%.
- Return on money staked. Total profit rewards the bot that traded most. Return on stake lets you compare two bots.
- One trade carrying the record. Remove the biggest win and look again. A longshot strategy can be good and still needs a bigger sample.
- Trades a week. A bot that makes two trades a month takes a year to prove anything. The builder shows this number before you start.
A checklist for going from paper to live
Paper is an option on Rivo, not a gate. You can go live on day one or stay on paper for a season. When you move, work through this list:
- Check the sample. Several dozen settled trades, more for longshots.
- Check the size. The paper record was made at the size you will trade live.
- Connect the venue account. A Kalshi API key, a Polymarket US account or a Gemini API key. Orders go through your own account. Rivo is not an exchange and holds no funds.
- Place one trade by hand. Leave the ticket on Live and compare the fill with what paper showed you.
- Take the bot live from its own page. The trigger and the size carry over.
- Set a per-trade limit and a daily limit. Start below your paper size.
- Set a loss limit. New live bots start with one filled in at five times the daily amount. At the limit the bot pauses, and you choose whether it also sells its positions.
- Read the live log next to the paper record. Every copy a live bot attempts is logged, including each skip and its reason.
One difference to expect: your paper orders never moved the real book and your live orders will, and a paper trader bot recorded the trader's price where a live bot buys after them. Live fills run a little behind a paper trader bot's record. Small limits at the start are how you measure the gap. More on live bots is on the Autopilot page, and the longer argument is in paper trading a bot before going live.
Kalshi paper trading
Kalshi is the venue where paper teaches the most about fees, because the 0.07 rate and the round-up to the cent bite hardest on small orders near 50 cents. A paper order on Rivo fills against Kalshi's live book with that fee and the series fee multiplier. Kalshi also names many of its traders, so trader bots have real records to copy from the Kalshi leaderboard, and its 15 minute series suit market bots. Kalshi runs its own demo environment with mock funds as well. The comparison, a worked order and the path to a live Kalshi key are on the Kalshi paper trading page, with fee tables in Kalshi fees explained.
Polymarket paper trading
Polymarket names a wallet on every trade, which makes it the richest venue for trader bots and signal bots. A paper order fills against the live book for the outcome you picked, with the market's own fee. Paper needs no wallet. Bots on Polymarket run as alerts or on paper, and you place real orders by hand through your browser wallet. See the Polymarket trading bot page.
Polymarket US paper trading
Polymarket US is a separate regulated venue with its own account, markets and order books. A paper order there walks the Polymarket US book and pays that market's fee coefficient. Its public trades carry no trader names, so paper bots on Polymarket US are signal bots and market bots. Live trading by hand and by bot runs through your connected Polymarket US account. The two Polymarkets are compared in Kalshi vs Polymarket.
Gemini paper trading
Gemini's prediction markets charge the same 0.07 taker rate as Kalshi, rounded up to the cent. A paper order fills against Gemini's live book with that fee. Gemini's trades are anonymous, so signal bots and price rules are the paper bots to run there, and live trading goes through your own Gemini API key.
Paper orders through the API and MCP
The same paper order is one call from code. POST /v1/paper-orders in the REST API places a market order on one outcome, named by its market reference, at the venue's live prices and fee. It needs the write scope, because no money moves. The MCP server offers it as the place_paper_order tool, so an AI agent can research a market, place a paper trade and report the fill in one conversation. Developers testing a Kalshi client of their own will also want the demo hosts in the Kalshi API guide.
Frequently asked questions
What is paper trading in a prediction market?
Placing a trade with no money behind it and tracking the result as if the trade were real. A good paper trade uses the live order book, the venue's real fee and the market's real settlement, so the only difference from a live trade is the money.
Can you paper trade Polymarket?
Yes. On Rivo you open any Polymarket market, switch the order ticket to Paper and place the order. The fill comes from Polymarket's live order book with the market's own fee, and the position settles when the market resolves. You need no wallet for a paper order.
Does Kalshi have paper trading?
Kalshi runs a demo environment at demo.kalshi.co with mock funds and its own markets. Rivo adds paper trading on live Kalshi markets, filled against the real order book with Kalshi's taker fee. The Kalshi paper trading page compares the two.
Is there a prediction market simulator?
Rivo's paper mode works as one. It covers Kalshi, Polymarket, Polymarket US and Gemini, fills paper orders from each venue's live book and settles them on the real result. It also runs three kinds of bot on paper.
What does paper trading cost on Rivo?
Paper trading is included in the Rivo subscription, $9 a week or $15 a month. Both plans include the same product: the terminal, paper orders, paper bots, the paper portfolio, alerts and live trading through your own venue accounts.
Do I need a Kalshi or Polymarket account to paper trade?
No. A paper order needs no venue account, no API key and no wallet. You connect a venue account only when you want to place real orders on that venue.
Do paper trades include fees?
Yes. A paper order placed by hand pays the venue's own taker fee, and the fee counts as part of your cost. Paper profit on a hand-placed trade is profit after fees.
Can I paper trade with a bot?
Yes. A trader bot records every buy a chosen trader makes at your size. A signal bot records every incoming trade matching your signal. A market bot runs a price rule on one market or a repeating series. All three run on paper on every venue Rivo tracks.
How long should I paper trade before going live?
Count settled trades, not days. Several dozen settled trades give you a return worth reading, and a strategy built on longshots needs more. Paper is optional on Rivo, so you can also start live at a small size with tight limits.
Is paper trading the same as backtesting?
No. A backtest scores a strategy on trades already recorded and markets already settled. Paper trading runs the strategy on the trades happening next. Rivo does both: the bot builder backtests a trader or a signal first, and a paper bot carries the record forward.