Global Araç
Stock Portfolio Diversification
| Sembol | Sınıf | Tutar | % |
|---|---|---|---|
| VTI | Endeks fonu | $30,000 | 54.5% |
| AAPL | stock | $10,000 | 18.2% |
| VXUS | Endeks fonu | $8,000 | 14.5% |
| MSFT | stock | $5,000 | 9.1% |
| BTC | crypto | $2,000 | 3.6% |
- VTI is 54.5% of the portfolio — concentration risk.
- AAPL is 18.2% of the portfolio — concentration risk.
- VXUS is 14.5% of the portfolio — concentration risk.
Çoğu yatırımcı için hedef: %80+ düşük maliyetli endeks fonlarında, bireysel hisselerde küçük bir uydu ve varsa kripto ≤ %5. Kazananların sessizce yoğunlaşma riskine dönüşmemesi için yılda bir kez dengeleyin.
Diversification is the closest thing finance has to a free lunch — owning a portfolio of uncorrelated assets reduces risk without reducing expected return. Modern Portfolio Theory (Markowitz, 1952 Nobel Prize-winning work) established the math: risk-adjusted returns improve with diversification across stocks, sectors, geographies, and asset classes. Practical guidance: any single stock above 10% of total portfolio is a concentration risk yellow flag (Enron, Lehman, Silicon Valley Bank moments destroyed concentrated positions); single-sector exposure above 30% is similarly risky (tech-heavy portfolios looked great 2010-2021 but lost 30%+ in 2022 sector rotation). The standard advice for most retail investors: 80%+ in low-cost index funds (VTI, VXUS, BND covers global stocks + bonds), 20% or less in individual stocks for those who want the “fun” of stock picking.
The tool takes your holdings (paste ticker + dollar amount or share count per line), then visualizes concentration: per-position percentage, per-sector allocation, geographic exposure (US vs international), asset-class split (stocks / bonds / cash / alternatives). Flags any position above 10% as concentration risk and any sector above 30% as sector risk. Useful for: annual portfolio review, rebalancing triggers, stress-testing “what if my biggest position drops 50%”, and confirming your portfolio actually matches your stated risk tolerance. Most investors discover their portfolio is more concentrated than they realize — picking individual stocks accumulates over years until one or two positions dominate.
Common diversification mistakes the tool surfaces: (1) Employer concentration — stock options + 401(k) employer-stock match + ESPP can put 30-50% of net worth in your employer's stock. If the company struggles, your job AND retirement both suffer (Enron employees lost both salary AND retirement). Sell vested employer stock periodically to stay below 10%. (2) Home country bias — Most US investors have 70-90% in US stocks despite US being only 60% of global market cap. Adding international (VXUS) provides diversification. (3) Sector concentration via single ETFs (QQQ is 50% tech, often added on top of already-tech-heavy holdings — double- counting sector exposure). (4) “ Diversification within a sector” — owning AAPL + MSFT + GOOG isn't diversification; they all crash together in tech-sector rotations. (5) Bond neglect — many growth-focused retail investors hold zero bonds; even conservative portfolios benefit from 10-30% bonds for crisis protection (bonds typically rise when stocks crash, providing rebalancing opportunity).
Nasıl Kullanılır
- Paste your holdings (ticker + dollar amount or share count per line).
- Read per-position percentages with concentration warnings (any over 10%).
- Read per-sector allocation; over 30% in one sector is concentration risk.
- Read geographic and asset-class splits.
- Plan rebalancing actions to reduce concentration.
Ne Zaman Kullanılır
- Annual portfolio review.
- After a position has run up significantly — confirming you're not over-concentrated.
- Before retirement — stress-testing your portfolio against worst-case scenarios.
- After major life changes (job change, inheritance, major bonus).
- Comparing two portfolio strategies (current vs target allocation).
Ne Zaman Kullanılmaz
- Strict tax-aware rebalancing — that needs cost-basis data and tax-loss harvesting integration.
- Hedge-fund-style risk modeling — needs more sophisticated risk metrics (Sharpe, beta, factor exposure).
- Crypto-heavy portfolios — needs crypto-specific risk modeling beyond standard equity diversification.
- Retirement-account-only review — needs glide-path / target-date considerations.
Yaygın Kullanım Senaryoları
- Educational use — demonstrating the underlying concept
- Onboarding a colleague who needs the same calculation/conversion
- Verifying a number or output before passing it on
- Quick use during a typical workday
Sık Sorulan Sorular
What's a concentration risk?
Any single position over 10% of total portfolio. Risks: company-specific blow-ups (Enron 2001, Lehman 2008, SVB 2023, Bear Stearns) destroy concentrated positions overnight. Even “safe” companies (GE, Sears, Kodak) can lose 90%+ over years. Reduce concentration by selling down or by adding to other positions to dilute. Avoid letting any one stock exceed 10% via gains; sell partial when crossing thresholds.
How many stocks do I need?
Research shows 20-30 stocks captures most diversification benefit (further additions have diminishing returns). For most retail investors, single-fund index ETFs (VT for global stocks, VTI for US, VXUS for international) provide instant diversification across thousands of stocks at very low cost (0.03-0.07% expense ratio). Picking 30 individual stocks is harder than buying VT and forgetting about it.
What's home country bias?
Tendency to overweight your own country's stocks. Most US investors hold 70-90% US stocks despite US being only 60% of global market cap. Limits diversification benefits. Mitigation: hold an international fund (VXUS, VEA, VWO) for 20-40% of equity allocation. International exposure provides diversification when US has rough decade (e.g., 2000-2009 US lost ground while international gained).
Are bonds important?
Yes for most investors. Bonds typically rise when stocks crash, providing portfolio stabilization and rebalancing opportunity. 10-30% bonds for moderate-risk portfolios; 40-60% for conservative or near-retirement. Many young growth-focused investors hold zero bonds — fine if you can stomach 50% drawdowns and have 30+ year horizon. For most adults, some bond allocation reduces portfolio volatility meaningfully.
What about employer stock?
High concentration risk. Stock options + 401(k) match + ESPP can put 30-50% of net worth in your employer. If company falters, you lose your job AND your retirement (Enron, Bear Stearns, Silicon Valley Bank). Standard advice: sell vested employer stock down to under 10% of net worth periodically. Tax-deferred 401(k) employer-stock match is especially risky because most people don't notice the accumulation. Diversify away from your employer.
When should I rebalance?
Two common triggers: (1) Threshold-based — rebalance when any allocation drifts more than 5 percentage points from target (e.g., target 60% stocks; rebalance when above 65% or below 55%). (2) Time-based — rebalance annually regardless of drift. Threshold tends to optimize returns; time-based simplifies execution. Tax-aware: in taxable accounts, prefer rebalancing via new contributions to underweight allocations rather than selling overweighted positions (avoids capital gains).