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

# Margin Accounts

> One PDA per wallet. Live vault balances are collateral. Debt is shares.

`MarginAccount` is seeded `["margin", authority]`. Status, collateral indexes, debt indexes, event sequence, and a compact Lite registry live on that account.

## Collateral

There is **no** `CollateralPosition` ledger. The associated token account owned by the margin PDA is the credit. Health reads its live amount.

That is safe because the vault is private to one (margin, mint). A donation cannot change anyone else's exchange rate. Shared `Reserve` vaults are the opposite: they keep `accounted_liquidity_assets` and ignore surprise transfers.

Every named or remaining-accounts vault is checked against `get_associated_token_address(margin, mint)`.

## Debt

`DebtPosition` stores **shares**, not a token amount. Interest grows `Reserve.total_borrow_assets`. One O(1) reserve update reprices every borrower.

```text theme={null}
user_debt_tokens = ceil(user_shares × total_borrow_assets / total_borrow_shares)
```

## Lifecycle

```text theme={null}
create → deposit → borrow / swap / lite_open
                ↘ repay → withdraw → close (empty)
                ↘ liquidate (HF ≤ 1.10)
```

`MAX_ASSETS = 24` bounds both collateral and debt slots so every health scan is a fixed cost.