In all seriousness though, large pension plans have very diverse portfolios. Ontario teachers used to own 80% of the Toronto Maple Leafs. Ontario Municipal Employees Retirement System owns Oxford Properties, which owns and manages the office building I work in (and many others).
Edit: Added "Employees" to OMERS.
Maybe not over (specific) very short periods, but it depends on the mutual and it depends on the hedge fund. If you're saying pension funds should be locked in then you can't invest in anything that has exposure to equities, see: 2008, 1974, 1930.
I was just trying to nudge the post I was replying to into realisation that you either accept burning significant money to avoid risk or accept the chance of burning more money. This kind of "pensions should invest in the good guys who don't take risks..." well that's only govt bonds, and one day those will pop also.