> For the complete documentation index, see [llms.txt](https://docs.symm.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.symm.io/trader-documentation/building-a-trading-bot/part-1-one-time-on-chain-setup/fund-the-sub-account.md).

# Fund the sub-account

Trades reference the sub-account's collateral balance on the Symmio core. You need balance there before you can open anything.

**Signed by:** Owner EOA, two transactions.

**Function:** First, `approve(spender = AccountLayer, amount = max)` on the collateral token, then [`depositForAccount(subAccount, amountWei)`](https://intent.symmscan.com/inspector/hyperevm/account-layer?method=0x342fcda9) on the AccountLayer.

`depositForAccount` (note: not `depositAndAllocateForAccount`) pulls the collateral from your EOA and credits it to the sub-account's balance on the Symmio core. The AccountLayer signs the inner `deposit` call to the core on your behalf via its `globalSigner` mechanism, so from the core's perspective the sub-account is the depositor.

You can re-run this any time you want to top up. You can also withdraw and re-deposit: the sub-account is sticky, the balance isn't.


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.symm.io/trader-documentation/building-a-trading-bot/part-1-one-time-on-chain-setup/fund-the-sub-account.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.