The two shapes
Pressure moves smoothly; the response is a step function.
The relationship between exposure pressure and authorised throughput is not proportional, and the shapes of the two series are the reason reading them together is informative. Pressure is continuous — it can sit at a third of the pool this cycle and two fifths the next, moving in small increments as carryover accumulates. Throughput does not respond continuously. Trade count holds at four while remaining capacity divided by four stays above the viability floor, and then drops to three, then two, in discrete steps as the floor is crossed. So the operator's experience is of nothing happening for several cycles and then an abrupt reduction, while the underlying quantity has been drifting the entire time. The abruptness is an artefact of the floor, not of the account, and the drift was legible throughout.
Schematic across eight cycles. Authorised trade count is unchanged for five cycles and then steps down twice in three. The pressure series carries the same information from cycle two onward, in a form that can be acted on before the step arrives.

