Every halving cycle so far has produced a smaller multiple than the one before it.
Size explains much of that.
When bitcoin was small and thinly traded, modest inflows could move price by orders of magnitude. Today it is a global macro asset with a much larger holder base.
Cycle 4 also skews the chart. Bitcoin set a new all-time high in March 2024, ahead of the halving, while earlier cycles started far below their prior peaks.
With the halving-day price already elevated, much of the run came before day zero, which holds the 1.3x below what a typical start would have produced.