Split, Merge, and Convert are three actions that let you restructure a Polymarket position without crossing the order book - so you change exposure or free up cash at the fair $1.00 value instead of paying the bid/ask spread. They look advanced, but each is a single idea. This guide explains exactly what each one does, when to use it, and why some outcomes get filtered out of the Convert dialog.

By the Polymarkets.co.il editorial team. Last reviewed: June 2026.

The short version

  • Split: 1 USDC → 1 Yes + 1 No of the same market. Mint both sides; keep one, sell the other.
  • Merge: 1 Yes + 1 No → 1 USDC. Redeem a matched pair for cash, instantly, at $1.00.
  • Convert (to Yes): multi-outcome only - turn No shares across the other outcomes into 1 Yes of your target + freed USDC.
  • All three trade at the fair $1.00, so you skip the spread a normal sell would cost.

Why these exist

Every Polymarket share is a claim worth $1.00 if it wins and $0 if it loses. A full set - one Yes and one No of the same market - is therefore always worth exactly $1.00, because exactly one of them pays out. Split, Merge, and Convert are the tools that move between collateral (USDC) and shares at that guaranteed $1.00 value, instead of buying or selling individual shares into the order book and paying the spread. On multi-outcome (NegRisk) markets, the same logic extends across a whole field of outcomes.

Split - mint a Yes/No pair from USDC

Split takes 1 USDC and gives you 1 Yes share + 1 No share of the same market. You now hold both legs. Keep the side you actually want and sell the other.

Why bother instead of just buying? Two reasons:

  • The side you want is illiquid. If "Yes" has a thin book but "No" is deep, you can Split for $1.00, then sell the No leg into the deep side - often a better fill than buying Yes directly.
  • You want to provide liquidity. Split gives you inventory on both sides to quote into the book.

Because a Yes/No pair is always worth exactly $1.00, splitting never moves the market against you - there is no spread to pay on the mint itself.

Merge - redeem a pair back into USDC

Merge is the exact reverse of Split: 1 Yes + 1 No of the same market becomes 1 USDC.

If you ever end up holding a fully matched pair - say you bought Yes earlier and later bought No to hedge - merging lets you exit both legs at exactly $1.00, instantly, without crossing the spread twice or waiting for the market to resolve. It is the clean, zero-slippage way to unwind a hedged position and get your cash back.

Convert (to Yes) - the capital-efficiency move

Convert is the one that only works on multi-outcome NegRisk markets - markets like "Who wins the 2028 nomination?" where many outcomes exist but exactly one will resolve Yes. Because of that structure, the Yes prices across all outcomes sum to about $1.00.

Here is the key insight: holding No on every other outcome is logically identical to holding Yes on the one that remains. If everyone else loses, your one survivor wins. So if you are long a basket of No shares across the field, Convert lets you swap them for:

  • 1 Yes share of your target outcome, plus
  • residual USDC - the collateral you no longer need to back the basket.

As the deeper NegRisk guide puts it: 1 No across all other markets converts to 1 Yes + residual USDC - the mechanism that enforces the $1.00 sum. Use it when you want to free up cash while keeping the same economic exposure, or to turn a messy field of No positions into a single clean Yes.

Convert only filters to real outcomes

Multi-outcome fields sometimes carry placeholder slots - bracket positions like "Team AH" or "Team AG" before the teams are decided. The Convert dialog filters those temporary/unused outcomes out (the same way the market page does), so they don't clutter the list or distort the basket math. You always convert against the real, active outcomes only.

When to use each

You want to...UseWhy
Get a position whose side is illiquidSplitMint both legs at $1.00, sell the deep side
Exit a matched Yes/No pair you already holdMergeRedeem for $1.00 instantly, no spread
Free up cash from a basket of No positionsConvertNo-basket → Yes + residual USDC
Flip a field of No shares into one clean YesConvertSame exposure, simpler position

Fees and what to check

Split, Merge, and Convert are mint/redeem actions priced at the fair $1.00, so you are not paying the trading (taker) fee or the bid/ask spread you would pay selling into the book. There is on-chain gas, which Polymarket's interface generally abstracts for you on Polygon. Always confirm the exact figures shown in the dialog before submitting - on a Convert in particular, the residual USDC you receive depends on how many outcomes you are converting.

How to start

These actions appear on the market page and in your portfolio once you hold the relevant shares. If you are new, get the basics first, then come back to these once you are running multi-leg positions:

Ready to trade? Here is the official Polymarket link → (affiliate link - free to use, doesn't change your fees or odds).

Frequently asked questions

What are Split, Merge, and Convert on Polymarket?
Three on-chain actions for restructuring positions without crossing the order book. Split mints a Yes/No pair from USDC. Merge redeems a matched Yes + No back into USDC. Convert turns a basket of No shares across the other outcomes of a multi-outcome (NegRisk) market into a Yes share of your target plus freed collateral. They change exposure or free cash at the fair $1.00 value instead of paying the spread.
What does Split do?
Split takes 1 USDC and mints 1 Yes share + 1 No share of the same market. You hold both legs and can keep the side you want and sell the other. Useful when the side you want is illiquid, or to provide liquidity on both sides. Splitting is always priced at exactly $1.00, so it never moves the market against you.
What does Merge do?
Merge is the reverse of Split: 1 Yes + 1 No of the same market redeems back into 1 USDC. If you hold a fully matched pair, merging exits both at exactly $1.00 instantly, without crossing the spread or waiting for resolution. It is the clean way to unwind a hedged pair.
What does Convert (to Yes) do?
Convert exists only on multi-outcome NegRisk markets. If you hold No shares across all the other outcomes, converting turns them into 1 Yes share of your target plus residual USDC - because No on everything-else is logically the same as Yes on the one remaining. It frees cash while keeping equivalent exposure.
When should I use each one?
Split to get a position when the side you want is illiquid. Merge to redeem a matched Yes/No pair for $1.00 instead of selling each leg into the spread. Convert when you are long a field of No positions and want freed cash or clean Yes exposure on one outcome. All three avoid the bid/ask spread a normal sell would cost.
Do Split, Merge, and Convert cost fees?
They are mint/redeem actions priced at the fair $1.00, so you avoid the trading (taker) fee and the spread you'd pay selling into the book. There is on-chain gas, which Polymarket's interface generally abstracts on Polygon. Confirm the amounts in the dialog - the residual USDC on a Convert depends on how many outcomes you hold.
Why are some outcomes (like 'Team AH') missing from the Convert dialog?
Multi-outcome markets sometimes include placeholder or not-yet-determined outcomes - bracket slots like 'Team AH' or 'Team AG' before the teams are decided. The Convert flow filters those temporary/unused outcomes out, like the market page does, so they don't clutter the list or break the basket math. You convert against the real, active outcomes only.
Which markets support Convert?
Only NegRisk multi-outcome markets - where Yes prices across outcomes sum to about $1.00 because exactly one resolves Yes (elections, tournament winners, 'who will be next...'). Plain binary Yes/No markets support Split and Merge but not Convert, which relies on the mutually-exclusive field structure.

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