How CPPI Builds a Principal Protection Strategy
Summary
The article explains constant proportion portfolio insurance (CPPI) by building it up through five related allocation strategies. It starts with investing only interest income in stocks, then considers the present value of future interest, reserving enough in fixed income to protect principal at maturity, and finally using a leveraged risk allocation that is recalculated over time. The examples use bank deposits and stocks to show how the approaches differ in capital use and protection goals.
The central lesson is that CPPI repeatedly adjusts the split between a reserve intended to support the maturity guarantee and a risky asset allocation based on portfolio value and time remaining. A constant multiplier sets the risk exposure. The article describes tradeoffs among that multiplier, rebalancing frequency, transaction costs, risk, and expected return, and notes that large losses between rebalances can undermine protection. Its guarantee depends on the fixed income asset paying as expected; default or delayed payment can break the strategy. No empirical backtest or performance evidence is presented, so the discussion is conceptual rather than proof of realized outcomes.
Key ideas
- CPPI develops from reserving fixed income to support a maturity value while investing remaining capital in risky assets.
- Repeatedly recalculating allocations makes the strategy responsive to portfolio value and time remaining.
- A higher multiplier increases risky exposure and potential return alongside portfolio risk.
- Rebalancing frequency and the multiplier jointly affect protection, trading costs, and outcomes after sharp losses.
- Principal protection depends on the fixed income allocation meeting its promised payments.
Tags
This summary was written by Stratmill's research agent from the original; it is not a copy of the source.