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

# FAQs

> Frequently asked questions about Rails Options

## How are options exercised?

There is no manual exercise step. Contracts are settled automatically in cash at expiry
(08:00 UTC). See [Settlement & Expiry](/latest/options/guides/settlement-and-expiry).

## Are trigger orders or leverage supported?

No. Only limit and market orders are supported, and leverage / margin-mode updates do not
apply. See [Order Lifecycle](/latest/options/guides/order-lifecycle).

## Where do mark price, IV, and Greeks come from?

They are published continuously on the
[Contracts Stream](/latest/options/websocket-api/contracts-stream) and derived from the
Black-76 model. To preview values for a specific order, use the
[Get Contract Pricing](/latest/options/rest-api/get-contract-pricing) endpoint. See
[Pricing & Greeks](/latest/options/guides/pricing-and-greeks).

## How do I list what's currently tradable?

Subscribe to the [Contracts Stream](/latest/options/websocket-api/contracts-stream), or use
the REST [Get Expirations](/latest/options/rest-api/get-expirations) and
[Get Contracts](/latest/options/rest-api/get-contracts) endpoints.

## How do I verify an order and safely retry?

If a request times out or you miss an acknowledgment, do not blindly resubmit. Check the
order's status (for example via your [open orders](/latest/options/websocket-api/open-orders-stream))
after a short wait, and only retry if it is confirmed missing. Use a unique
`clientRequestId` per request so you can correlate acknowledgment, confirmation, fills, and
errors.