This strategy is always an option. Put all your money in Treasury bills - the "risk-free" investment - and forget about it.
It is practised by every successful investor when they can't find an investment that meet their criteria, they don't invest at all.
Even this simple rule is violated by far too many professional fund managers. For example, in a bear market they'll shift their portfolio into "safe" stocks such as utilities, or bonds ... on the theory they'll go down less than the average stock. After all, you can't appear on Wall Street Week and tell the waiting audience that you just don't know what to do at the moment.