Hedge-fund pricing
The vol surface that takes three minutes.
Your vol surface has 6,000 cells — 200 strikes times 30 maturities. Every time the market moves, the surface has to be re-priced. Today the inner loop is a time-stepper: Crank-Nicolson, BDF, ADI. It marches through hundreds of small steps from τ=0 to τ=T for every single cell. The 6,000-cell surface takes three minutes. The trader waits.
Imagine a pricing engine that computes the answer at T directly — one contour integral, one LU factorization reused across every strike in the same vol bucket. The 6,000-cell surface takes two seconds. The trader doesn’t wait.