
Final salary pensions have been as rare as rocking horse shite since 2000 (i joined ICL/Fujitsu in 1999 and missed out on the Final Salary pension by about 6 months), anyone who got one after that is very lucky. Pensions tend to follow the markets and there is a lot that can spook the markets, economic downturns i.e. housing crash, Brexit, war, even US elections can have an impact. The US have a big impact as most trading is done in dollars.
I work for an FX trading company but i am in IT so don't really understand it.