I keep meeting investors who own thirty different stocks and call it a diversified portfolio. Twenty-eight of those positions usually share two factors: US large-cap and growth. When 2022 happened, the entire "diversified" portfolio dropped 28% in nine months because the exposures were never really different — just spread across thirty tickers.

Diversification is about uncorrelated risk drivers

A portfolio is diversified to the extent that its components respond differently to the same shock. Two tech stocks listed in different countries are not diversified — they share the same factor exposure. A short-dated EU bond, an oil major, a REIT, and a small Bitcoin sleeve, however, will each react to different things.

So instead of asking "how many positions do I have," we ask "how many independent risk drivers do my positions touch?" The answer is rarely more than five or six, even in a large portfolio.

The Milkos five-driver map

  • Equity earnings risk — global stocks, broadly diversified.
  • Interest-rate risk — duration through government and high-grade corporate bonds.
  • Inflation risk — real assets: REITs, infrastructure, commodities.
  • Credit risk — investment-grade and a small slice of senior-secured high yield.
  • Monetary alternative — a thin allocation to gold and, for some readers, Bitcoin.

If your portfolio touches all five, you are already more diversified than 80% of the reader portfolios we review.

The three rebalancing rules that quietly do the work

Diversification only persists if you rebalance. Otherwise the asset that ran up the most will silently dominate the portfolio. Our three rules:

1. The 5-percentage-point band

If any driver drifts more than 5 percentage points from its target weight, we rebalance back to band — not all the way to target. This avoids over-trading on small moves while preventing one driver from quietly taking over the portfolio.

2. The 12-month minimum

We never rebalance more than once per quarter, and never less than once per year. Frequent rebalancing in calm markets adds costs without adding returns. The 12-month floor catches everything that matters.

3. New money first

Where possible, we rebalance by directing new contributions toward the underweight driver. This avoids realising taxable gains and reduces friction. The "sell to rebalance" lever is reserved for when contributions are insufficient.

"A great portfolio is one you can leave alone. Rebalancing exists so you can leave it alone for longer." — Note from our 2024 quarterly review

Three traps we see every quarter

Home bias on autopilot

Romanian and EU investors routinely hold 70–90% of their equity sleeve in EU large caps. That is a single-driver bet on the European economy. Even adding 25–30% US exposure dramatically reduces single-country risk.

Treating crypto as an asset class

Crypto is not a single asset class — it is a basket of very different bets (monetary alternative, smart-contract platforms, infrastructure plays). For diversification purposes we treat only Bitcoin and ETH as portfolio constituents and require any sleeve to be sized so a 60% drawdown does not break the plan.

Overpaying for "exotic" diversifiers

Managed futures, market-neutral funds, and absolute return strategies have a place — but most retail versions charge 1.5%+ to deliver something a 60/30/10 portfolio already covers cheaper. Read the prospectus before paying for elegance.

What a Milkos-style portfolio looks like in 2025

For a moderate-risk reader in their late thirties with a 20-year horizon, our current template lands around: 50% global equities, 25% short and intermediate bonds, 12% real assets, 8% gold, 5% Bitcoin. The numbers are illustrative — the point is the spread across the five drivers.

If yours looks dramatically different, that is fine — what matters is whether you can answer the question "which driver does this position cover?" for every line.

Where to go from here

Open your statement. Tag each line to a driver. Count the drivers, not the tickers. Then check whether the weights match your declared targets. If they do not, you have a calm, manageable rebalance to plan over the next month.