That means there is Haskell in the keyword search but its not necessarily a Haskell job. A lot of companies, mine included, have problems with agents stuffing all sorts of shit in job ads just to get candidates to sign up.
Haskell seems an unlikely word to stuff in. I can find a few in a quick search (eg Jane Street who are well known for Haskell).
Have you looked at the large investment banks (Barclays, HSBC, Credit Suisse etc) or any major hedge funds?