It all depends on what your version of the apocalypse is. until it eventuates, then derisking yourself is the most profitable trade going, and depends on how high maintenance your lifestyle is now.
pay down all essential debts, get at least one residence free of all and any incumberances. pay off your credit cards (in preparation below). taking some profits out of rising investments to pay these down.
if you think it is a global catastrophe of any kind, including a universal meltdown of currencies, then physical possession of PM's would be my choice. cash money would be useless, but you'll need some in the early days - and perhaps markets have been locked out also.
if the markets continue to function, then like everything that exists today, you will see and hear where money is shifting to via the trendlines.
if hyperinflaiton becomes a reality, then money in the bank won't matter also. food, fuel, insurance premiums, etc will skyrocket - so you'll need something to trade.
... then go the way of the banks. When it tips over, get yourself into hopeless amounts of debt, live on stupid amounts of credit (not your money), and bankrupt yourself when it all falls apart using bank credit.
The 2 responses above are not mutually exclusive - just make sure any tangible assets are not in your name. It takes 1 month to sell a property, and 4 days to get cash from shares.
If it becomes another armageddon, unit trusts will lock up like they did in 2008, and banks will close. Extrapolate this and assume that all managed funds, banks and stockmarkets will be locked up - so having some cash under the bed makes sense, and be in possession of your PM's.
Emergency powers would be frightening if you want to get even marginally realistic. Don't assume you'll get 1:1 return on any of your assets if that is the case and they end up frozen.
But until then, enjoy the trends and derisk yourself as much as possible.
