THE GLOSSARY · MARKETS
Variance
The natural swing of results around their average. A negative year does not prove a strategy is broken — and a good year does not prove it works.
By the Yoseri News desk · · 1 min read
Variance — the gap between what a strategy produces over a short period and what it produces on average over a long one.
It is the idea that explains why one year of return says almost nothing. A portfolio whose expected real return is 5% a year will go through years at −15% and years at +22%. Both are normal; neither is a signal.
The practical consequence is counter-intuitive: the shorter the horizon, the more chance dominates; the longer it is, the more the average comes through. That is why a thirty-year retirement projection is more reliable — as an order of magnitude — than a twelve-month forecast.
The corollary holds for your own decisions too: judging a savings rule on two months makes no sense. Two months under the rule out of twelve, both tied to a drop in income, describe an ordinary year — not a failure.
In Yoseri, the Savings and goals page shows what pauses and what carries on when an income stops. Two months under your rule read there as a sequence, not as a failure.
Yoseri News is an educational publication. Nothing in this article is investment advice, a recommendation to buy or sell, or tax advice. Yoseri is registered as neither an adviser nor a dealer with any market authority.