Banky team Reviewed editorial answerA variable-return deposit's rate = a reference rate + the bank's margin. The reference can be one of the Central Bank's rates (such as the overnight deposit rate or the credit-and-discount rate) or the average interbank overnight rate, and the bank sets the margin in the product's terms.
When a new rate applies after the reference changes is set in the deposit's terms. For variable-rate certificates the rule is that it applies after the current payout period's return is credited, not from the day of the decision; check the timing for your deposit specifically.
A hypothetical example per 100 EGP: a reference of 20% and a margin of 0.5% give 20.5% a year, and the monthly payout is about 1.71 EGP. If the reference became 19%, the payout would be 1.625; if it became 21%, about 1.79. This is not a forecast of where rates are going.
That is why any figure you see today for a variable return is an expected return at today's rate and can change. Check the key-facts statement: the reference rate, the margin, and when the rate is adjusted.