.. index:: FHCF, Financial Structures; FHCF, Florida Hurricane Catastrophe Fund

Florida Hurricane Catastrophe Fund (FHCF)
=========================================

Graphene provides a default built-in template for modelling conventional
FHCF contracts. The default template for FHCF supports the following
financial features:

- occurrence attachment and limit

  - The full occurrence attachment will apply to the 2 occurrences with the largest losses in a given trial.
  - 1/3 of the occurrence attachment will apply to the remaining occurrences.

- aggregate attachment and limit
- upfront premium income
- contract inception / expiration dates
- participation
- currency exchange

Structure
---------

The general structure of a default FHCF using the built-in template in
Graphene is:

.. code-block:: json

    {
        "_schema": "FHCF_1.0",
        "inception_date": 1546300800,
        "expiration_date": 1577836800,
        "occurrence_attachment_value": 10000,
        "occurrence_limit_value": 30000,
        "aggregate_attachment_value": 20000,
        "aggregate_limit_value": 50000,
        "premium_value": 3000,
        "share": 0.2,
        "currency": "GBP"
    }

Parameters
----------

The parameters are defined as follows:

+---------------------------------+----------+------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Parameter Name                  | Required | Type       | Description                                                                                                                                                                                                                                                                                                   |
+=================================+==========+============+===============================================================================================================================================================================================================================================================================================================+
| ``inception_date``              | Yes      | ``double`` | Timestamp on which the contract incepts. The coverage period is **inclusive** of this time.                                                                                                                                                                                                                   |
+---------------------------------+----------+------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| ``expiration_date``             | Yes      | ``double`` | Timestamp on which the contract expires. The coverage period is **exclusive** of this time.                                                                                                                                                                                                                   |
+---------------------------------+----------+------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| ``occurrence_attachment_value`` | Yes      | ``double`` | The occurrence attachment or retention of the contract in currency units.                                                                                                                                                                                                                                     |
+---------------------------------+----------+------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| ``occurrence_limit_value``      | Yes      | ``double`` | The occurrence limit of the contract in currency units.                                                                                                                                                                                                                                                       |
+---------------------------------+----------+------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| ``aggregate_attachment_value``  | Yes      | ``double`` | The aggregate attachment or retention of the contract in currency units.                                                                                                                                                                                                                                      |
+---------------------------------+----------+------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| ``aggregate_limit_value``       | Yes      | ``double`` | The aggregate limit of the contract in currency units.                                                                                                                                                                                                                                                        |
+---------------------------------+----------+------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| ``premium_value``               | Yes      | ``double`` | The amount of premium paid upfront in currency units. Premium is paid at time of inception.                                                                                                                                                                                                                   |
+---------------------------------+----------+------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| ``share``                       | Yes      | ``double`` | The share or participation assumed for this contract.                                                                                                                                                                                                                                                         |
+---------------------------------+----------+------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| ``currency``                    | No       | ``string`` | The currency in which the input currency values (``occurrence_attachment_value``, ``occurrence_limit_value``, ``aggregate_attachment_value``, ``aggregate_limit_value``, ``franchise_deductible_value``, and ``premium_value``) are defined. Defaults to the :ref:`base currency <base-currency>` if not set. |
+---------------------------------+----------+------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

Output Records
--------------

The FHCF financial structure can produce 2 different types of records:

- ``Loss``: Layered losses, that is losses that are covered by the contract.
  Losses generally have a negative value.
- ``Premium``: Upfront premium paid at
  the time of inception. Premium is accounted for as a positive credit.

References
----------

A detailed description of the financial modelling internals of the FHCF
structure can be found in :doc:`fhcf_step_by_step`.