October 2026 · Insurance
A 2.5 million member pension buy-in, priced in 41 seconds.
Every member valued on every one of 600,000 possible futures, end to end, on one workstation. No model points. No shortcuts.
What we ran.
- 01
Every member, one by one
2.5 million people, each with their own age, pension and cap on increases. No model points, no averaging into groups.
- 02
Every year of every life
Each member projected a year at a time to age 120: will they be alive, how much will their pension rise, what will it cost, what is that worth today.
- 03
Across 600,000 futures
Each future a different path for how long people live, for gilt yields and for inflation: the three risks a buy-in is priced on.
An hour and a half, or a minute.
The same model and the same method, written as fast as we could make it in C and run on all 32 threads of the same computer. Then on its graphics card, with Henselian.
- Hand-optimised C, every core
- 93 minutes
- Henselian, one graphics card
- 41 seconds
Drawn to scale. 137 times faster on equally optimised code. The C run was timed on 640 of the 600,000 futures and scaled; the Henselian run is measured end to end.
The numbers.
A synthetic scheme on an illustrative mortality basis, so nothing here is any scheme's real figures. The scale and the time are real.
- Members
- 2.5 million
- 1.6 million pensioners, 900,000 deferreds
- Futures
- 600,000
- longevity, gilt yields and inflation
- Member-futures
- 1.5 trillion
- 100 trillion member-years
- Time, end to end
- 41 seconds
- three runs: 40.8 s, 41.0 s, 44.4 s
- Best estimate liability
- £321.3 billionstandard error £25 million
- Best estimate at 1-in-200
- £374.7 billionthe 99.5th percentile of 600,000 futures
- Capital, 1-in-200 less best estimate
- £53.4 billion16.6% of the best estimate
- Premium
- £334.1 billionbest estimate with a 4% pricing margin
Checked, not just fast.
With every source of randomness switched off, the graphics card and our reference interpreter agree to every printed digit. The hand-written C agrees with both, and on the full scheme within the margin you would expect from 600,000 futures.
Measured 25 October 2026. One NVIDIA RTX 4090 and an Intel i9-13900KF (24 cores, 32 threads), in the same workstation.
What it means if you price buy-ins.
Quote on every member
Price the scheme as it is, person by person, instead of on model points that smooth away the members who matter most.
Rerun when the basis moves
A change to mortality, yields or inflation is a minute away, not an overnight queue. Ask again before the call ends.
Know the tail before you sign
The 1-in-200 comes from 600,000 futures of the whole book, in the same run as the price.
We cannot prevent every storm. We can help you prepare before it arrives.
Bring us the simulation your organisation wishes it could run faster. We will show you what is possible, on a book shaped like yours.