Insurance Fund

An insurance fund is a reserve held by a derivatives exchange or a decentralized protocol to absorb losses that would otherwise fall on other users. In crypto, the term usually refers to funds run by exchanges that offer leveraged products such as perpetual futures. When a trader's position is liquidated and cannot be closed at a price that covers their debt, the shortfall is paid from the insurance fund, so that the traders on the winning side still receive their full profits.

The idea has parallels in traditional finance. Clearing houses for futures and options keep default funds paid in by their members, and many countries run deposit insurance schemes that protect bank customers. A crypto exchange insurance fund is narrower: it is usually financed from the exchange's own liquidation proceeds, covers only trading losses on its derivatives platform and gives users no legal guarantee. Its size is often published so traders can judge how well protected the market is.

Picture a poker table where players can borrow chips from the house to make bigger bets. If a player loses more than they own and walks away, someone has to cover the debt to the winner. The house keeps a jar of spare money for exactly that purpose, topped up whenever it closes out a losing player for less than expected.

An exchange's insurance fund is that jar. When markets move calmly, the jar grows. When prices crash or spike suddenly and many borrowers are wiped out at once, money is taken out to pay the winners. If the jar runs dry, the exchange has to use other, less popular methods to balance the books.

Traders using leverage post initial margin and must keep a minimum maintenance margin. If the market moves against them and their margin falls below that level, the exchange takes over the position and closes it, a process described under forced liquidation. The exchange tries to close the position at a price better than the trader's bankruptcy price, the price at which their margin would be exhausted.

• Surplus. If the liquidation is closed at a better price than the bankruptcy price, the leftover margin is usually added to the insurance fund rather than returned to the trader.
• Deficit. If the market moves so fast that the position can only be closed at a worse price, the fund pays the difference.
• Fees. Some exchanges also add part of their liquidation fees to the fund.

Because surplus from orderly liquidations usually exceeds deficits from disorderly ones, funds on large exchanges have grown into substantial sums. Exchanges typically publish fund balances, which change daily.

If losses exceed the insurance fund, exchanges use fallback mechanisms. Auto-deleveraging closes part of the positions of profitable traders on the opposite side, ranked by profit and leverage, to offset the loss. Older systems used socialized losses, in which a share of all winners' profits was clawed back. Both are unpopular, so a larger insurance fund is a selling point, and some exchanges have injected their own money to replenish funds after extreme events, such as cascading liquidations during a flash crash.

Decentralized protocols use similar ideas. Decentralized derivatives platforms often hold insurance funds, sometimes topped up from trading fees, to cover bad debt from liquidations. Lending protocols may hold reserves from part of the interest paid by borrowers, or ask holders of a governance token to stake it in a safety module that can be partly used to cover shortfalls. Separate on-chain cover products let users buy protection against smart-contract failures, although these are not insurance in the regulated sense. In each case, the fund is only as strong as its size, the assets it holds and the rules for using it, a concern addressed in many DeFi risk frameworks.

• No legal guarantee. Exchange insurance funds are discretionary and do not protect users if the exchange itself fails or is hacked; that is a separate custody risk.
• Concentrated assets. Funds are often held in the exchange's own token or in a single cryptocurrency, which may fall in value during a crash.
• Transparency. Users must rely on the exchange's reports of the fund's size unless balances can be verified on-chain.
• Cost to traders. Because surplus margin goes to the fund, liquidated traders lose more than they strictly need to.