Stock markets price fractional ownership in companies with open-ended time horizons, while prediction markets price the probability of specific future events that resolve to a yes or no outcome on a fixed date. That single structural difference, binary event versus ongoing equity claim, is the root of nearly every other distinction between the two: how contracts settle, how traders think about edge, what regulation applies, and why the same person can profitably trade one and lose money in the other.
For traders coming from equities into prediction markets for the first time, the surface similarities are seductive. Both have order books, bid-ask spreads, volume, and probability-like prices. Both reward being right about the future. But the mechanics underneath are different enough that the skills, strategies, and risk-management rules do not transfer cleanly. Understanding where the two diverge is the difference between treating prediction markets as a new asset class and treating them, incorrectly, as “stocks with a weird expiration date.”
What Each Market Actually Prices
A share of stock is a residual claim on a company’s future cash flows. When you buy Apple at $230, you own a tiny slice of the discounted present value of every dollar Apple will ever earn, minus its obligations, divided across every share outstanding. The price moves on earnings, macro conditions, interest rates, sentiment, and thousands of other variables that influence that cash-flow estimate.
A prediction market contract is a binary claim on a specific event. “Will the Fed cut rates by 25 bps at the December meeting?” trades between 0 cents and $1. If the event happens, the “Yes” contract settles at $1. If it does not, “Yes” settles at $0. The price in between, say 72 cents, is the market’s consensus probability: 72%. There is no residual value, no dividend, no compounding. You are buying a probability, not a cash-flow stream.
Time Horizon and Settlement
This is where traders coming from equities get surprised most often. A stock position can be held for a day, a decade, or forever. A prediction market contract has a hard expiration date baked into the contract specification. On that date, the event either happened or it did not, and the contract settles to $1 or $0. There is no “wait for it to come back.”
Settlement is also determined by a fixed resolution source, not by the market itself. A Kalshi contract on CPI, for example, settles to the Bureau of Labor Statistics release. A Polymarket contract on an election settles to the Associated Press call or a similar pre-specified source. Traders need to read resolution criteria carefully, because an unexpectedly ambiguous outcome can be more painful than being wrong about the event itself.
Liquidity, Volume, and Market Depth
Stock markets are deep. Mega-cap names trade billions of dollars a day, spreads on liquid names are a penny wide, and institutional flow absorbs large orders without moving the tape meaningfully. Prediction markets are growing fast but remain comparatively thin. A high-profile Kalshi contract might have a few million dollars in open interest; a flagship Polymarket election market can hit nine figures around a presidential race, but smaller markets often clear on a few thousand dollars of volume.
The practical implication: in equities, you can usually ignore your own market impact unless you are trading size. In prediction markets, posting even a mid-sized bid can move the price several cents, and getting out of a position before resolution sometimes requires accepting a worse price than your fair value implies.
Regulation and Market Structure
| Feature | Stock Market | Prediction Market |
|---|---|---|
| Primary US regulator | SEC, FINRA | CFTC (for Kalshi and other DCMs) |
| Contract type | Equity security | Event-based binary contract |
| Settlement | Ongoing, dividends + sale | Fixed date, $1 or $0 |
| Typical holding period | Days to decades | Hours to months |
| Short selling | Separate borrow mechanic | Buy the “No” side directly |
| Leverage | Margin, options, futures | Generally cash-only |
| Tax treatment (US) | Capital gains, dividends | Short-term gains on most contracts |
Kalshi operates as a CFTC-regulated designated contract market (DCM), which is why it can offer event contracts to US residents through a compliant onshore structure. Polymarket uses a crypto-based structure that historically has not been open to US retail traders, though the landscape is evolving. Equities, by contrast, operate under the SEC’s framework for securities, with a mature ecosystem of exchanges, broker-dealers, clearinghouses, and investor protections.
How Edge Works in Each Market
In equities, edge usually comes from one of three places: better information, better models, or better execution. Fundamental investors dig into financials; quant funds exploit statistical relationships; market makers earn the spread. The opponent is sophisticated, and the easy money has largely been arbitraged away in liquid names.
In prediction markets, edge is often more accessible for retail traders because the pool of participants is smaller and the markets are newer. Three sources of edge recur:
- Domain expertise. If you know a specific sport, policy area, or technical field cold, you can often spot mispriced contracts that generalist traders miss.
- Resolution-criteria reading. Markets sometimes trade on the headline question rather than the exact settlement rule. Traders who read the fine print find edges.
- Timing around catalysts. Prices around debates, economic releases, and court rulings often overreact. Patient traders exploit the mean reversion.
Equity traders bringing standard tools, DCF models, options Greeks, technical patterns, sometimes find them less useful on prediction markets, where the right mental model is closer to poker or sports handicapping than to valuation.
Risk Profile and Position Sizing
A diversified equity portfolio has a positive expected long-term return, driven by the equity risk premium. Buy-and-hold, properly diversified, is a strategy that works across decades. Prediction markets have no such baseline return; every trade is a zero-sum bet against another participant, minus fees. Sizing matters enormously: a prediction market trader who bets too large on a single event can wipe out an account on one wrong call, because the contract will settle at $0 with no possibility of recovery.
The implication is that prediction markets reward Kelly-style sizing, where positions scale to your assessed edge and the size of the market, rather than lump-sum allocation strategies that work in equities. Traders accustomed to “I like the stock, I’ll put 5% of the portfolio in” need to rethink that heuristic when a single binary event can take the position to zero in a week.
Which Is Right for You?
They are not substitutes. Most serious traders who use prediction markets also hold a traditional equity portfolio; the two serve different functions. Equities build long-term wealth through compounding. Prediction markets let you express sharp views on specific outcomes, hedge real-world risks like election results or Fed decisions, and extract edge from informational advantages that equities would never reward. If you are new to the space, the sensible path is to keep your equity allocation intact and carve out a small sleeve, often 1 to 5 percent of liquid assets, to explore prediction markets with capital you can afford to see settle at zero.
Ready to try prediction markets alongside your equity portfolio? Start with the two most established platforms: Kalshi, the CFTC-regulated US leader, and Polymarket, the global crypto-based market with the deepest political and crypto contracts. For a full comparison of the top venues, see our best prediction markets rankings.