Portfolio Construction: The Core-Satellite Strategy for Diversified Alpha

Strategy Overview

Core-satellite portfolio construction combines passive, broad market exposure (the 'core') with actively managed, higher-conviction strategies (the 'satellite'). The core typically comprises 70-90% of the portfolio. It invests in low-cost ETFs or index funds tracking major indices like the S&P 500 or MSCI World. The satellite portion, 10-30%, allocates to specific sectors, themes, or individual securities. This structure provides diversification and stability from the core. It offers potential for outperformance from the satellite.

Core Component

Investment Vehicle

Use broad-market, low-expense ratio ETFs. Examples include SPY, IVV, VOO for US equities; VT for global equities. For fixed income, consider BND or AGG. Select funds with expense ratios below 0.10%. These vehicles provide market beta exposure efficiently. They minimize tracking error.

Allocation Rules

Maintain a fixed percentage allocation to the core. Rebalance annually or semi-annually. If the core drifts by more than 5% from its target weight, trigger a rebalance. For example, if the core target is 80%, rebalance when it reaches 75% or 85%. This keeps the portfolio aligned with its passive foundation.

Risk Parameters

The core's risk aligns with market risk. Diversification across asset classes within the core reduces idiosyncratic risk. Limit exposure to any single core asset class to 60%. For example, US equities 60%, international equities 20%, bonds 20%. This provides a baseline risk profile.

Satellite Component

Strategy Focus

Satellite strategies pursue specific alpha generation. Examples include long/short equity, global macro, event-driven, or sector rotation. Each satellite segment should have a distinct investment thesis. Avoid overlapping risk exposures between satellite positions. For instance, a technology growth fund and a semiconductor ETF might share too much correlation.

Entry Rules

Define clear entry triggers for each satellite position. For long/short equity, enter a long position when a stock shows relative strength above its 200-day moving average and trades at a P/E below its sector average. Enter a short position when a stock shows relative weakness below its 200-day moving average and trades at a P/E above its sector average. For sector rotation, enter a sector ETF when its 3-month performance exceeds the S&P 500 by 2% and its RSI (14) is above 60. Use specific quantitative metrics.

Exit Rules

Establish strict exit rules. For long positions, exit if the stock closes below its 50-day moving average for two consecutive days. Exit if it declines 10% from its peak. For short positions, cover if the stock rallies 5% from its entry price. Cover if it closes above its 50-day moving average for two consecutive days. For sector ETFs, exit if the sector underperforms the S&P 500 by 1% over one month. Exit if its RSI (14) falls below 40. Define maximum holding periods for satellite positions, e.g., 6-12 months, unless the thesis remains strong and conditions favorable.

Position Sizing

Allocate 1-5% of the total portfolio to each individual satellite position. Do not exceed 10% for any single satellite strategy. This limits the impact of any single underperforming bet. The aggregate satellite allocation should not exceed 30% of the total portfolio.

Risk Management

Implement stop-loss orders for all satellite positions. Set hard stops at 8-12% below entry for long positions. Set hard stops at 8-12% above entry for short positions. Review satellite positions weekly. Reassess their thesis against market conditions. Cut losing positions quickly. Do not average down on underperforming satellite bets. Maintain a maximum drawdown limit of 15% for the entire satellite component. If breached, reduce all satellite positions by 50%. This prevents outsized losses from active management.

Practical Application

An investor with a $1,000,000 portfolio might allocate $800,000 (80%) to the core. This $800,000 could be split: $500,000 in SPY, $200,000 in VXUS (international equities), and $100,000 in BND (US aggregate bonds). The remaining $200,000 (20%) goes to satellites. This could involve four positions of $50,000 each. One position might be a long/short equity strategy focusing on technology. Another could be a clean energy ETF. A third might be a global macro trade in a specific currency pair. The fourth could be an emerging markets small-cap fund. This diversified approach leverages passive efficiency and active alpha seeking. It balances risk and return potential. Regularly review both core and satellite components. Adjust allocations based on market outlook and strategy performance. Maintain strict discipline on entry, exit, and risk parameters.