Sales that begin immediately after the holiday period are clearing a specific problem. The stock involved was bought for a demand peak that has now gone.
Buying for a peak means overbuying
Seasonal demand is forecast months ahead from previous years, and the forecast is always wrong in one direction or the other.
Being short is expensive in a visible way, because a customer who cannot buy goes elsewhere and the sale is lost outright at the highest-margin moment of the year.
Being long is expensive in a quieter way. Retailers generally choose to be long, which guarantees a surplus once the peak passes.
Why the sale starts so quickly
Demand for seasonal goods does not taper. It falls away almost immediately once the occasion has passed, and the stock loses relevance overnight.
Holding it for a year means paying to store it, financing it, and accepting that next year's range will make it look dated on arrival.
Clearing at a loss now is frequently cheaper than storing at a cost for twelve months, which is why reductions begin within days rather than weeks.
What is actually left
The stock remaining is the stock that was least wanted, which means unpopular colours, extreme sizes, and specifications that were never the sensible choice.
Occasion-specific goods are the clearest case. Their value collapses the moment the occasion ends, which is why discounts on them are the steepest available all year.
Alongside this sits genuinely good stock that was simply overbought, and distinguishing the two is the practical skill in shopping a clearance period.
The stock that was bought for the sale
Retailers also buy specifically to sell during the clearance period, because footfall is high and shoppers arrive expecting reductions.
This stock is new, arrives in full size runs and is priced to a target rather than reduced from a previous price, which distinguishes it from real clearance.
It sits alongside genuine markdowns under the same signage, and the distinction is visible mainly in availability and in whether the product was ever sold at the higher price.
Why the next season is already on display
Ranges are planned around a calendar that runs ahead of the weather, so spring stock arrives while winter clearance is still underway.
Selling space is the constraint, and full-margin new stock earns more per square foot than discounted old stock, so clearance is consolidated into a smaller area.
That consolidation is the signal the period is ending. When clearance moves to the back of the shop, the remaining reductions are the last ones offered.