Comprehensive Guide
Learn more in our Investing Guide.
How it works
Commodity sleeves earn their slot through explosive, mean-reverting cycles — oil doubling in a year, then giving it back — which makes them the textbook candidate for disciplined rebalancing. This calculator quantifies one cycle's arithmetic: given a target weight, a tolerance band and an illustrative move for both commodities and the rest of the portfolio, it computes the post-move allocation, checks the breach and sizes the exact trade restoring target. Start at 10% commodities in a $200,000 portfolio, hand commodities a +30% year against +8% elsewhere, and the sleeve swells to roughly 11.9% — drifting nearly two points past a ±3-point band? Not quite; widen the commodity rally to 45% or tighten the band to 2 and the breach fires, demanding a trim near $4,600 that banks proportional gains while restoring balance. The mechanism is mechanical sell-high/buy-low with no forecasting involved: bands throttle how often the machine trades, trading tax efficiency for tracking tightness. Honest caveats apply throughout — rebalancing disciplines behavior and controls risk, but does not guarantee higher returns; in taxable accounts every trim realizes gains; and the move percentages here are illustrations you set, not projections anyone can promise.Formula
New weight = w(1+m_c) ÷ [(w)(1+m_c) + (1−w)(1+m_s)] | Trade = |new value × target − sleeve value| when |drift| > band
Tips
- Bands of 2–5 absolute points balance discipline against churn and taxes.
- Rebalance commodity trims inside tax-sheltered accounts where possible.
- Wide-band rebalancing deliberately lets winners run before banking anything.
- Pair with the calendar: check bands quarterly, act only on breaches.
- No rebalance rule guarantees outperformance — it enforces risk control and humility.