Lifecycle investing is the broader framework that views a person's financial life as the joint management of human capital (the present value of future earnings) and financial capital (current investable assets). At any age, the optimal portfolio considers both stocks of capital, not just the visible portfolio.
Core insight: when young, human capital is large and bond-like (stable salary). The financial portfolio should be all-equity to balance the bond-like human capital. When older, human capital has shrunk; the financial portfolio must do more of the risk-bearing and the volatility-cushioning, so it should be more conservative. This is the analytical foundation for the glidepath.
Ayres and Nalebufs' lifecycle investing book argues younger investors should even lever up their equity exposure (e.g., 200% equity via margin) to better match the equity dollars across decades. The argument is mathematically defensible but practically risky for retail in India given financing costs, margin calls, and behavioural risk.
Example 1: A 28-year-old engineer earning Rs 24 lakh with 30 years of expected income has perhaps Rs 4-6 crore of human-capital present value vs Rs 5 lakh financial portfolio. Even an all-equity Rs 5 lakh portfolio is a small slice of total wealth — they are still hugely "underweight equity" relative to total wealth. SIPs to scale this up are rational.
Example 2: A 60-year-old with Rs 0 human capital and Rs 3 crore financial portfolio cannot afford 60% equity — a 50% equity drawdown shrinks portfolio by 30%, irrecoverable without years of earning power. A 30-40% equity allocation balances inflation protection and drawdown control.
Lifecycle investing also informs insurance (protect human capital while it is large) and emergency fund sizing (relative to human-capital stability).
Disclaimer: Educational content from MintByte (ARN-314872, MFD). Examples are illustrative. SEBI Investment Adviser registration is in process; we do not provide personalized lifecycle-planning advice.