Sequence risk means the order of investment returns can matter when withdrawals are happening. Two portfolios can experience the same set of annual returns over a period, but in a different order. When money is being withdrawn along the way, the ending result may be different because withdrawals interact with market values.

The key distinction is cash flow. If there are no contributions or withdrawals, the order of the same annual returns does not change the final value. Sequence risk appears because the portfolio remains invested while it is also being used to fund spending. Assets withdrawn after weak early returns are no longer available to participate fully in a later recovery.

Sequence risk is usually most visible around the years just before and just after retirement. A downturn before retirement can reduce the starting portfolio, while a downturn soon after retirement can combine lower market values with withdrawals. This does not mean weak markets automatically cause retirement failure; it means the timing of returns is one assumption that should be tested.

Canadian retirement income often comes from a mix of sources. CPP/QPP, OAS, workplace pensions and annuities may reduce dependence on market withdrawals, while RRSP/RRIF, LIF, TFSA and non-registered accounts create different tax, liquidity and account-rule considerations. The portion of spending that must be funded from market-exposed assets is usually the portion most exposed to sequence risk.

Sequence risk cannot be eliminated by one product, account order or rule of thumb. It can be examined through planning levers such as withdrawal rate, spending flexibility, cash reserves, asset allocation, predictable income sources, tax/account sequencing and regular review. A useful projection does not try to predict the exact return sequence; it asks how the plan behaves if weak returns occur early.