process
Simplicity as design
The rule
A simple three-fund plan you can actually hold beats a busy clever one you cannot. Simple is a smart choice, not a weakness.
Where it flips
But treating 'three funds' as a rigid law can fail a truly complex household. Foreign spending, a family business, or special tax needs may call for a fourth slice. Three funds is the default test, not a ceiling for every life.
Bogle said a plan's real job is to be lived with. A few broad, low-cost slices for growth, stability, and one steady diversifier can cover every job a household plan needs. A busy ten-fund account often just looks clever while hiding heavy overlap, higher cost, and a mess too tangled to rebalance calmly. Three is not a magic number; it is a test. If three broad slices do the job, any extra fund must earn its own separate job. A simple plan is easier to check, easier to rebalance, and harder to turn into a game that tempts you to fiddle. The plan you can hold through a bad year beats the clever one you drop.
A worked example
A household holds one broad index fund, one short-term debt fund, and a small gold slice, each with a written target. A neighbour's ten-fund plan has more lines but 78% overlap. Busier to watch, harder to rebalance, no clearer. [illustrative]
How to spot it
- ·each slice can name its own separate job
- ·overlap is checked so extra funds are not secret copies
- ·the plan is simple enough to rebalance and check calmly
John C. Bogle · The Little Book of Common Sense Investing