How Bids and Asks Work on Kalshi and Other Prediction Markets

How to Read Bids and Asks on Prediction Markets Like Kalshi

Kalshi makes the Bid-Ask pricing easier to track because it shows the order book. You can see the Bids, the Asks, and how many contracts are available at each price before you place a trade.

Many other prediction market apps don't show that level of detail. In some cases, you can see a single price, which makes it harder to judge the spread, available liquidity, and how much your trade could move the market.

The order book is a live list of open buy and sell offers on a contract, sorted by price. The Bid side is the buy side, ranked from the highest price offered down to the lowest. The Ask side is the sell side, ranked from the lowest asking price up. The gap between the best Bid and the best Ask is the spread.

If the best Bid is 7.2 cents and the best Ask is 7.6 cents, the spread is 0.4 cents. If someone tries to trade at a price in the spread, their contract won't be filled right away and will instead become a Bid on the order book.

A limit order lets you do exactly this on purpose. Instead of taking whatever price is on offer, you pick your own, below the Ask when buying, above the Bid when selling, and wait for someone to match it. In the example below, the limit buy is placed at 7.4 cents, right in between the Bid (7.2 cents) and Ask (7.6 cents), so it waits in the book instead of executing right away.

The last traded price (which controls the % that Kalshi shows) is useful too, but it only tells you where the most recent completed trade happened.

On a market list like the one below, each row shows a percentage next to the Yes and No prices, and that percentage is the last traded price, not the current Bid or Ask. That means it can lag what's available once you click into the market. For example, “Reg Time: Over 2.5 goals scored” shows 52%, meaning the last completed trade happened at 52 cents, but the actual Bid and Ask you'd see after clicking in could already be different.

When you're deciding whether to enter a position, the current Bid and Ask are more important. They show the prices available right now, not where the market last traded at, which could have been hours ago.

The YES + NO = $1 Relationship

Here's something that trips up a lot of new Kalshi traders who don't know how prediction markets work: YES and NO contracts aren't independent markets. They're two sides of the same $1.00 contract. One of them will pay out $1.00, and the other pays $0.00, without exception. If YES is trading at 60 cents, NO has to be at 40 cents.

The reciprocal pricing changes how the order book works under the hood. A YES Bid at 60 cents is mathematically identical to a NO Ask at 40 cents. Kalshi's API only exposes Bid data for this reason, because the Ask on one side is always derivable from the Bid on the other.

One thing to watch for: the Yes and No prices on a market list are both Ask prices, what you'd pay to buy each side. They're not a matched Bid and Ask. That's why they'll often add up to a little more than $1.00, since each side has its own small markup built in. 

Look at the Strait of Hormuz market below. On the “Before Nov 1, 2026” question, Yes is 37 cents and No is 64 cents, totaling 101 cents, not 100. The exact $1.00 split only shows up when you compare a Bid on one side to the Ask on the other.

The platform's UI shows both columns, but there's really just one set of prices driving the market. When you check the order book, you're looking at the same pricing from two angles. Go back to the Hormuz example: Yes at 37 cents and No at 64 cents aren't two separate markets, just two sides of the same one, priced from opposite directions.

What Kalshi's Order Book Layout Tells You

Kalshi shows parallel columns, “Buy YES” on the left and “Buy NO” on the right. The side-by-side layout makes the complementary pricing easy to spot. Look at the depth behind each column, and you can tell a lot about market health.

If there are a lot of orders close to the best Bid and Ask, the market is usually easier to trade. Buyers and sellers are close on price, so you don't have to give up much to enter or exit.

If the next price levels are far apart, liquidity is thinner. The top Bid and Ask might look fine at first, but a larger order can push you into a worse price pretty quickly.

The order book also shows contract volume at each price level, and it's not always evenly distributed.

In the example below, the best Ask (37 cents) only has 110.7 contracts sitting at it, worth about $41. One level down on the Bid side, 36 cents has over 15,000 contracts available, worth more than $5,400. That's a big difference in depth, just one cent apart.

A bigger size at a price level means you can enter a meaningful position there without moving the market.

A thin level means even a modest order could push you to the next price.

How the Spread Affects Your Entry Price

When you place a market order to buy, you pay the Ask. When you place a market order to sell, you get the Bid. This applies to taker orders specifically, which are orders that execute immediately against whatever's already resting in the book.

If you buy a contract and hold it to settlement, the spread doesn't cost you anything you've actually lost. Your outcome still comes down entirely to whether the contract resolves in your favor. What the spread does affect is your entry price relative to fair value: paying the Ask instead of the true midpoint means you're starting from a slightly worse number than a perfectly efficient trade would give you.

The spread only becomes a real, realized cost if you buy and then sell right back out with the market otherwise unchanged, a round trip.

Say the Bid is 48 cents and the Ask is 52 cents. You buy at 52, then sell immediately at 48. Nothing about the event changed; you just gave up the 4-cent spread on the way in and out.

The spread cost isn't a Kalshi fee. It goes to the traders on the other side of your order. Even so, it comes out of your return the same way any other trading cost would, but only if you're actually trading in and out, not sitting on a position.

On active markets like major election contracts or Fed rate decisions, spreads are often 1 to 2 cents. On thinner markets, niche political questions or obscure mentions markets, you can easily see spreads of 3 cents or more. 

Take the example below: a niche bracket on the Brazil presidential election margin of victory has a 3-cent spread (Ask 37 cents, Bid 34 cents), with as few as 5 to 10 contracts available at the top price levels.

If a spread is wide and you don't want to cross it, a limit order gives you a way around it. Place your buy order near the current highest Bid instead of paying the Ask, and wait for someone else to meet your price. You might not get filled right away, but when you do, you skip the spread entirely.

The big takeaway is that fees reduce winnings on a successful trade, while the spread affects your entry price before any outcome is reached.

Market Orders vs. Limit Orders

A market order (widely known as a “taker” order), called a “quick order” on Kalshi, buys or sells right away at the best price currently available. It's fast, but the price can be worse than the number you had in mind because you're crossing the spread.

A limit order lets you choose your price. You post a buy order below the current Ask or a sell order above the current Bid, then wait for another trader to match you.

The choice between the two matters most when the spread is wide. If the Bid is 48 cents and the Ask is 56 cents, a market buy gets you in at 56 cents right away. A limit order at 50 cents saves you six cents per contract if someone meets your price. On a 100-contract position, that's $6.00 in recovered edge.

Kalshi offers a few limit order variations worth knowing.

• GTC (Good ‘Til Cancelled) is the default setting. Your order stays open until it fills, you cancel it, or the market expires.
• IOC (Immediate-or-Cancel) executes whatever portion fills immediately and cancels the rest. Useful when you want a partial fill at your price but don't want an open order sitting in the book.
• EOD (End-of-Day) keeps your order live until market close if it doesn't fill right away.
• Custom gives you full control over the expiration. Just pick a date and time, like July 13, 2026, at 2:36 PM in the example below, and the order cancels automatically once that moment passes.

• At Event Start automatically cancels any unfilled portion of your order once the event begins. This is especially useful on mentions markets and similar contracts, where the market can resolve No before the event even ends. A resting No order can go stale fast in that scenario, so canceling at event start protects you from getting filled on an outdated price.

There's a fee incentive to use limit orders, too.

Kalshi separates makers and takers. If your order waits in the book and another trader accepts it, you're a maker. If you take someone else's available price right away, you're a taker.

Makers usually pay lower fees, and Kalshi offers maker rebates on select markets. That gives traders a real reason to be patient and post their own price instead of taking the market price immediately.

Polymarket has an even stronger incentive for patient orders. Maker orders cost 0% and earn a rebate, so you can get paid when another trader accepts the price you posted.

That makes limit orders especially useful on Polymarket. You're not just getting more control over your entry. You're also improving the fee math on the trade.

If you want to try out Polymarket, be sure to use promo code ODDSASSIST when signing up and depositing at least $20 to claim $50 in trading bonuses as a new user.

Speed is the main reason to use a market order. If a market is moving fast and you need to get in or out immediately, waiting for your price might cost you the trade entirely. Price control is worth less than execution speed in those moments.

What the Spread Actually Costs You

Most spread explainers stop at “tight spreads are good.” That's accurate, but not useful. The actual calculation is straightforward.

Spread cost = (Ask − Bid) × number of contracts

A 2-cent spread on 50 contracts costs $1.00. A 10-cent spread on 200 contracts costs $20.00.

This is the cost of a full round trip: buying at the Ask and later selling at the Bid, with the market otherwise unchanged.

You cross the spread once going in and once coming out, but since the Ask and Bid sit on opposite sides of the same gap, the total cost equals one spread-width, not two.

Here's a live example. On the Fed rate decision market below, the Ask is 79 cents and the Bid is 78 cents, a 1-cent spread. Say you think 79 cents is too low and the contract is really worth 82 cents, a 3-cent edge. Your round-trip cost is just 1 cent per contract. Since your edge (3 cents) is well above that cost, the trade works even if you end up exiting early, and if you hold to settlement instead, you avoid most of that cost entirely.

A limit order is how you avoid paying the full spread in the first place.

Instead of buying at the Ask, you can place your order near the current Bid and wait for someone else to meet your price. You won't always get filled, but when you do, you skip crossing the spread altogether, which is the cheapest way to enter a position.

How to Check Spread and Liquidity Before You Trade

On Kalshi, the spread is visible directly from the order book columns. The best YES Ask sits at the top of the YES Ask column, and the best YES Bid sits at the top of the YES Bid column. The gap between those two numbers is your spread.

A few warning signs that a market is thinner than it looks:

• Low historical trading volume on the market page is a reliable indicator of wide spreads during off-peak hours.
• Few contracts available near the current price, even when the top-of-book spread looks tight, signal limited depth.
• Large price jumps between order book tiers mean there's a hole in the book. If the next available buy price is 5 cents below the best Bid, volume at the top is misleading.

Here's that last warning sign in practice. In this niche entertainment market tracking Netflix's weekly rankings, the best Bid is 11 cents. The next level jumps to 10, then 9, then 7 cents, skipping 8 entirely. A large sell order could blow through several price levels before it fills, meaning you'd end up selling part of your position at 11 cents, part at 10, and part even lower, well below what the top-of-book price suggested you'd get.

For sports markets, Kalshi gets a real liquidity boost from its Robinhood integration, since order flow from Robinhood's Prediction Markets users routes directly into Kalshi's order book.

NFL, NBA, and MLB contracts benefit the most from that extra volume, often keeping buyer and seller prices within 1 to 2 cents of each other on popular games.

Politics and economic markets are more of a mixed bag. Some markets, like Fed rate decisions and major election contracts, draw enough traders to keep spreads tight.

Niche question markets, on the other hand, can see much wider spreads simply because fewer traders are watching them closely enough to compete on price.

Because liquidity varies so much market to market, it's worth checking the order book before you place a trade, especially in a contract you haven't traded before.

The headline price tells you where the market stands, but not whether there's real depth behind it.

How Odds Assist Helps You Find Better Entry Prices

Once you understand the spread, the next question is whether the price in front of you is worth taking.

That's where Prediction Markets Pro comes in.

Instead of treating every Kalshi market like a one-off guess, the dashboard gives you live pricing, historical data, and smart filters in one place. You can see how a market has moved, where traders are starting to price new information, and whether a contract has already run too far before you enter.

The mention trackers are especially useful for markets built around language.

For example, the Earnings Call Mentions Tracker lets you track phrases priced into Kalshi's earnings call markets and compare them against transcript data. If traders are pricing a term aggressively before a call, you can decide whether the number makes sense based on how often companies in that sector usually use similar language.

Prediction Market Bid and Ask FAQs

What is the Bid/Ask spread on Kalshi?
The Bid is the highest price a buyer is offering for a contract. The Ask is the lowest price a seller will accept. The spread is the difference between those two numbers, and it works like a built-in trading cost you pay every time you buy at the Ask or sell at the Bid.

Is it better to use a limit order or a market order on Kalshi?
A limit order gives you price control and can save you the spread cost, especially on wider markets. A market order is faster and guarantees a fill at the current Ask. Limit orders are the better option when price matters more than speed, which is most of the time. Market orders make sense when getting in or out immediately is worth paying the spread.

Why is the spread wider on some Kalshi markets than others?
Wider spreads show up in markets with fewer active traders. Major election markets or Fed rate contracts often have tight pricing because real competition between buyers and sellers drives prices together. Smaller, lower-volume markets have a bigger gap because fewer participants are willing to commit at current prices.

Does Polymarket have an order book like Kalshi?
Yes. Both platforms run central limit order books (CLOBs), and the core structure is the same. The display differs in that Kalshi shows both YES and NO columns side by side, while Polymarket shows one side at a time with a toggle.

Does the Bid/Ask spread count as a fee?
Not as an official platform fee. You won't see the spread listed the way Kalshi's trading fee shows up at settlement. But the spread still reduces your return on every trade. It goes to the traders on the other side of your order, not to Kalshi, but it comes out of your result either way.

Why does Kalshi's order book API show only Bids?
In a binary prediction market, every YES Bid at price X is mathematically equivalent to a NO Ask at ($1.00 minus X). Showing both would be redundant. The UI renders both columns visually for clarity, but under the hood, only Bids exist as distinct data points. Any client-side logic needs to calculate the Asks by subtracting the NO Bids from $1.00.