# Fee Breakdown ### Opening Fee A one-time opening fee is charged when a position is opened, designed to cover the cost of initiating trades **without charging again on close**. This fee is a flat rate for traditional (non-crypto) assets—e.g., a 4 bps fee, equivalent to 2 bps open + 2 bps close on other platforms—kept simple and predictable. More details [here](https://ostium-labs.gitbook.io/ostium-docs/ostium-trading-engine/opening-trades#protocol-opening-fee). {% hint style="info" %} There is a $0.10 upfront oracle fee for closing positions manually, which is entirely refunded after the trade is executed. Automated close orders (SL/TP) do not incur such a fee. {% endhint %} All pairs are subject to a fixed opening fee, regardless of leverage or Open Interest skew. *** ## Oracle Fee A flat **$0.10** fee charged whenever the protocol must fetch and attest an external price (oracle read) to process your action. This covers oracle and automation costs.\ For market **opens**, if the transaction reaches chain and fails for any reason, the oracle fee is still charged. The front end blocks most failure cases except **slippage**, so slippage is the most common reason you might see a fail with the fee consumed. ### When the oracle fee is charged (and refunded or not) | Action | Charged | Refunded | Notes | | ------------------------------------- | ------- | ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------- | | Open **market** order | Yes | No | If the open fails (including due to **slippage**), collateral is returned but the oracle fee is consumed. | | Open **limit** order (place) | Yes | No | Charged when placing the limit order. | | **Cancel** limit order | — | No | Collateral is returned, but the fee paid at placement is not refunded. | | **Partial close** | Yes | No | Charged per partial-close execution. | | **Remove collateral** (reduce margin) | Yes | No | Charged per request. | | **Full close (100%)** | Yes | **Yes, if successful** | Fee is charged upfront and **refunded** on a successful full close. If the close fails (e.g., slippage), the fee is **not** refunded. | *** ### Liquidation Fee If a position is liquidated, the trader’s remaining collateral is seized and paid out as a negative PnL to the Vault. More details [here](https://ostium-labs.gitbook.io/ostium-docs/ostium-trading-engine/closing-trades#liquidation). *** ### Price Impact Orders execute at the underlying bid or ask price based on the order’s side and type, unless the pair has **Dynamic Spreads** enabled—in which case execution occurs at the **Price-After-Impact**, a dynamically adjusted price that reflects real-time liquidity conditions and short-term order flow balance. Click [here](https://ostium-labs.gitbook.io/ostium-docs/dynamic-spreads) to learn more. *** ### Rollover Fee The rollover fee reflects underlying market carry costs, and is applied to all assets. * Charges may differ by side * Fees compound per block and are factored directly into unrealized PnL * Rollover fees are realized when the position is closed This fee covers the cost of carrying positions over time. More details [here](https://ostium-labs.gitbook.io/ostium-docs/broken-reference). The rollover fee is displayed on the Net Rate (L/S) label. Hover over it to display a tooltip explaining the long/short rollover fees.