> ## Documentation Index
> Fetch the complete documentation index at: https://docs.numofx.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Collateral

> What a trading account can hold, and how each asset counts toward margin

A trading account holds two assets: USDC and cNGN. Both back spot orders and futures margin in the
same account. No other asset is accepted.

## Accepted assets

Each token is held in a wrapped asset under the MarginEngine. You deposit and withdraw the token,
but the action's `asset` field names the wrapped asset.

| Token | Token address on Base | Wrapped `asset` | Minimum deposit |
| - | - | - | - |
| USDC | `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913` | cash asset, `0xA74E49b4Ed7cb176bc02ef4D8a1A3240C9aD4272` | 10 USDC |
| cNGN | `0x46C85152bFe9f96829aA94755D9f915F9B10EF5F` | cNGN escrow, `0x37c976bb5d4887a714ef19AF6B83e34fe2f37c98` | 15,000 cNGN |

[`GET /v1/markets`](/api-reference/endpoint/get) reports the cash asset as `quote_asset_address`, and the
cNGN escrow as the `asset_address` of `cNGN-USDC`.

## Decimals

You send amounts in the token's **6-decimal base units**: `1000000000` is 1,000 USDC, or 1,000 cNGN.
The account is credited at 18 decimals, so 1,000 USDC appears on chain as
`1000000000000000000000` of cash.

## How collateral counts toward margin

* **USDC** counts at par.
* **cNGN** counts at its base margin factor (`0.5`), valued at the index.
* While cNGN trades below its depeg threshold, the MarginEngine adds a penalty to initial margin.

All cNGN under the MarginEngine shares one cap, set on chain. A deposit that would cross it is
refused with a **400** that says how much room is left.

See [Margin](/futures#margin) for the initial and maintenance requirements on futures.

## Variation margin

Futures variation margin settles in cNGN. A payer pays from its cNGN first, then the rest from USDC
at the index. A winner is paid in cNGN while the engine's pool holds it, then in USDC. See
[Variation margin](/futures#variation-margin).

## Issuer controls

USDC and cNGN issuers can freeze wallets and pause their tokens.

* If an issuer has frozen your wallet, deposits and withdrawals of that token are refused with a
  **400** that says so.
* If an issuer has paused the token, or frozen a venue contract, deposits and withdrawals of that
  token are suspended for everyone with a **503**.

## Move collateral in and out

> **[Create a deposit](/api-reference/endpoint/deposits)**
>
> Open an account and fund it, or top it up. The venue pays the gas.

> **[Create a withdrawal](/api-reference/endpoint/withdrawals)**
>
> Withdraw to the account's owner without interrupting trading.


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