a) Are all derivatives held at fair value on the balance sheet or are there some exceptions?
b) Following is the link to an article from 2007 related to the use of derivatives by Southwest Airlines at a time when fuel prices were rising significantly. This article discusses how these derivatives's value to their income fell as fuel prices starting coming back down.
Research and find other examples of derivatives that have been used by other companies successfully (or not)?
https://www.usatoday.com/travel/flights/2007-04-19-southwest-posts-first-quarter-profit_N.htm