Past exam of the mathematics course of the University of Cambridge 2015 iii Paper 40 5 a Solution Created 2026-10-03 Updated 2026-10-06
Use a telescoping replication of a stock-price sum. Hold shares during interval ; at time , sell one share and keep its proceeds in the bond. Start with shares and no cash, costing .
After the time- rebalance, the stock holdings are and the cash holdings are , so wealth isThe sale of one share exactly funds the cash increase, making the strategy self-financing. Equivalently,At time there are no remaining shares, and the cash equals the claim. All stock positions over trading intervals are predictable.