Non-Proportional CoversAdvanced

Top-and-Drop Cover

Dropping down once a layer is spent

A protection sitting above a catastrophe tower that "drops down" to cover a lower layer's limit once that lower layer's reinstatements are fully exhausted.

Open the interactive version → definition, quiz, structure diagram and progress tracking

Definition

A top-and-drop cover normally attaches at a higher point in a cedent's catastrophe tower, but contains a provision letting it "drop down" to respond at a lower layer's attachment point once that lower layer's reinstatements have been fully used up within the same event or period. It gives cedents a further source of limit at the bottom of the tower without having to buy full additional reinstatements at the lower layer's own, typically more expensive, rate — its trigger and pricing are analysed together with the whole tower's reinstatement structure, not in isolation.

It activates only once a specified lower layer's reinstatements are fully exhausted — it does not respond automatically alongside every loss to that lower layer.
Its purpose is giving the cedent further limit at the bottom of the tower without buying full additional reinstatements at the lower, more expensive layer's own rate.
Because its trigger depends on another layer's exhaustion, it must be priced and analysed together with the tower's overall reinstatement structure, not as a standalone layer.

Worked example

A cedent's $10M xs $5M layer has one reinstatement, both fully used after two hurricanes in one season. A top-and-drop cover, normally attaching at $30M xs $20M, drops down to respond at the $5M attachment point for a third storm, since the lower layer has nothing left.

Scenario · figures in USD

A third storm with nowhere else to go

A cedent's $10M xs $5M layer has exhausted its original limit and single reinstatement after two hurricanes. A top-and-drop cover normally sits at $20M xs $30M but is designed to drop down once the lower layer is spent.

Lower layer	$10M xs $5M, one reinstatement
Status after two hurricanes	Original limit and reinstatement both fully used
A third hurricane produces a loss of	$8M
Lower layer's remaining capacity	$0 — nothing left to respond
Top-and-drop cover's response	Drops down to the $5M attachment point and pays the $8M loss

So whatThe top-and-drop cover exists precisely for this moment — when the lower layer has nothing left, it steps into the gap rather than leaving the cedent fully exposed for a third event.

Check your understanding

When does a top-and-drop cover activate at a lower attachment point?

Only once the specified lower layer's reinstatements are fully exhausted. A top-and-drop cover is contingent — it only drops down to a lower attachment point once that lower layer has no further reinstatements left to respond.

Why do cedents buy a top-and-drop cover instead of simply buying more reinstatements on the lower layer directly?

It gives further limit at the bottom of the tower without paying for full additional reinstatements at the lower layer's own, typically pricier, rate. A top-and-drop cover is a way of buying contingent limit at the bottom of the tower more economically than purchasing full extra reinstatements at the lower layer's own rate.

Word problem

A cedent's $8M xs $4M layer has one reinstatement and is fully exhausted (both the original limit and the reinstatement used) after two large losses in one year. A top-and-drop cover, normally attaching at $15M xs $20M, is designed to drop to the $4M attachment point once the lower layer is exhausted. A third loss of $6M then occurs. What does the top-and-drop cover pay, and why would this loss otherwise have gone entirely unreimbursed above the retention?

Show a hint

Confirm the lower layer truly has nothing left before checking what the drop-down layer covers instead.

Reveal the worked answer

The $8M xs $4M layer has used its original limit and its one reinstatement — its capacity for this year is fully exhausted.
Without the top-and-drop cover, a third loss above $4M would have no reinsurance layer left to respond to it at that attachment point.
Because the lower layer is exhausted, the top-and-drop cover drops down to respond at the $4M attachment point instead of its normal $20M attachment point.
The $6M loss falls within the dropped-down layer's capacity, so it pays the full $6M above the cedent's $4M retention.

The top-and-drop cover pays the full $6M, dropping down to respond at the $4M attachment point since the original $8M xs $4M layer had no capacity left. Without it, this third loss would have gone entirely unreimbursed above the retention, since the lower layer had already used both its limit and its only reinstatement.