What Kalshi’s New Fee Structure Means for Traders

As first reported by InGame, prediction‑market exchange Kalshi rolled out a new fee curve for “maker” orders earlier this month.

In an email to users, Kalshi said the change is “designed to better align with market dynamics and ensure long‑term liquidity,” while still ensuring that makers pay less than takers.

How the new fee is calculated:

fees = round up(0.0175 x C x P x (1-P))

C = The number of contracts being traded
P = The price of a contract in dollars (e.g., $0.50 is 0.5)

The formula replaces a flat 0.25‑cent charge per share, but only on markets that already carried maker fees. These include major sports events and a handful of macro-economics markets available on brokerages like Robinhood or Webull. Most other markets remain fee‑free for makers.

InGame did a deep dive into how the new maker fees will play out. Parsing through 11 million trades, they found that “the amount Kalshi would collect in fees is little changed whether the old formula or the new formula is used. Fees were slightly higher under the new formula, but the difference — the increase from $3.03 million to $3.06 million is negligible.”

But the impact isn’t evenly spread:

Here’s what else traders should know about the new formula.

Long shots and ‘bonds’ are cheaper than before

If you specialize in long shots or, on the opposite end of the spectrum, bonds, costs actually fall. Think outright golf winners that are closer to 1¢ or Fed fund rates that are nearly certain and are priced as such at 99¢.

The changes make it easier to provide liquidity at the tail end of the price distributions, where the previous flat fee made, as one trader said, “99¢ and 1¢ contracts unworkably costly relative to the risk/reward.”

Mid-range prices just got more expensive

If you aren’t trading on long shot winners or low return bonds, then your fees are getting more expensive when placing limit orders in the range of 17¢-83¢ — precisely where a lot of liquid sports contracts for game matchups lay before the events begin.

For pick’ems, where teams are pretty evenly matched, the maker fees nearly double in a 50-50 market —25 ¢ to ∼0.44 ¢ per share—eating half of a one‑tick scalp.

That can add up, especially for traders who profit via small edges and small flips, grabbing a cent here and a cent there.

Expect wider spreads

Because risk is highest at ~50¢, maker fees are now highest exactly where liquidity is most valuable. Some independent makers in Kalshi’s Discord signaled that they’ll stop quoting 1‑tick markets.

With fewer quotes and a higher risk premium, we could see spreads widen in some markets.

Picture this: You are an independent market maker who posts a limit order of 100 contracts at 49¢. Once its filled, you then flip the same 100 shares at 50¢. Under the old flat maker fee—a quarter‑cent per share—you paid 25¢ when you bought and another 25¢ when you sold, keeping 50¢ of the one‑dollar (one‑cent‑per‑share) spread. That 50‑cent cushion was enough to make the penny‑flip worth the hassle, especially at large volumes, for some traders.

Now insert Kalshi’s new quadratic fee. At the riskiest point of the curve—50/50 odds—the maker fee is roughly 44¢ per share. Your purchase costs 44¢, your sell costs another 44¢, so the same round‑trip leaves you with just 12¢ of the original dollar. In other words, the fee almost quadruples relative to the profit you were trying to pocket, squeezing your margin by about 75 percent.

How will traders adapt?

The first option is to widen the spread quoted. Move your sell price up to 51¢ instead of  50¢ and the gross gain doubles to two cents per share. After two 44¢ fees, you net about $1.12, finally beating the old one‑cent strategy.

Another workaround is to focus on contracts far from 50¢. At 10¢ or 90¢ the new fee drops to roughly 16¢ per share, restoring healthy economics for one‑cent flips. In those “long‑shot” or “near‑lock” territories you can still post tight quotes without watching the fee eat your edge.

Bottom line: in the middle of the price ladder, Kalshi’s new fee curve eats most of a one‑cent scalp, forcing makers to either accept thinner profits or quote wider spreads (which takers will notice).

Small orders pay a hidden “round‑up tax”

Fees are rounded up to the next cent, so order size matters. For example:

10 shares @ 48 ¢ → raw fee =$0.0437 → charged $0.05 → 0.50 ¢/share

1,000 shares @ 48 ¢ → raw fee =$4.37 → charged $4.37 → 0.437 ¢/share

The good news is that ​​If the extra fees caused only by rounding add up to more than $10 in a month, Kalshi automatically refund that excess in the first week of the next month. But fragmented fills still raise your upfront cost, and may be worth tracking to ensure you are reimbursed properly.