How It Works

Transparent methodology you can trust

Test Your Retirement Strategy Against Real Market History

SharkFintics helps you test retirement strategies using real historical market data from 1970 to present. See how your portfolio would have performed through multiple recessions, bull markets, and financial crises.

Test against 50+ years of market history
Real data from 1970-present
Compare multiple strategies
Find what works for you
Make data-driven decisions
Based on historical evidence
Understand plan resilience
Through economic cycles

The 6-Step Process

Key Concepts Explained

Sequence of Returns Risk

The Problem:

“Two portfolios with identical average returns can have vastly different outcomes based on the order of returns.”

Example:

✓ Retiree A: Retires in 1995
Strong bull market at start → Portfolio grows early → Success
✗ Retiree B: Retires in 2000
Dot-com crash at start → Early losses + withdrawals → Failure

Both had the same allocation and withdrawal rate. The only difference: when they retired. SharkFintics reveals this risk by testing your exact strategy against multiple start years.

Dynamic vs Static Withdrawal Strategies

Static Strategies

Fixed Dollar, Fixed Percent

How they work: Same rule applies regardless of market conditions

Pros: Simple, predictable income

Cons: Don't adapt to portfolio performance

Dynamic Strategies

Guyton-Klinger, SMILE (Pro tier)

How they work: Adjust withdrawals based on portfolio value

Pros: Potentially extends portfolio life, responds to markets

Cons: Variable income requires spending flexibility

Which is right for you? Test both in simulations to compare trade-offs between income stability and portfolio longevity.

What Makes SharkFintics Different

Real Historical Data

Not just Monte Carlo simulations. Test against actual recessions, crashes, and bull markets. Ground your plan in reality.

Multiple Withdrawal Strategies

Compare Fixed Dollar vs Fixed Percent vs Guyton-Klinger vs SMILE. Find the strategy matching your risk tolerance and flexibility.

Transparent Methodology

Open about data sources and calculations. No proprietary “black-box” algorithms. You understand exactly how results are generated.

Tier-Based Access

Free: Test with recent data (2009-present). Pro: Full dataset (1970-present), advanced strategies, profile comparisons.

Educational Focus

Not just a calculator – teaches retirement planning concepts. Resources library and methodology explanations help you understand “why” not just “what”.

Limitations & Assumptions

We're transparent about what our simulations don't include yet:

❌ Taxes: Simulations don't account for capital gains, ordinary income, or tax brackets. Actual withdrawals may need to be higher to cover taxes. (Coming Soon)
❌ Transaction Costs: Assumes rebalancing and withdrawals are cost-free. Real-world costs slightly reduce returns. (Generally minimal with modern low-cost brokers)
❌ Healthcare Costs: No specific modeling of Medicare premiums or out-of-pocket medical expenses. Can be included manually in annual spending. (Coming Soon)
❌ Social Security: Not yet integrated. Can be modeled manually by reducing withdrawal amounts. (Coming Soon)
❌ Pensions & Annuities: Not directly modeled. Can account for by reducing required withdrawals. (Coming Soon)

Important Disclaimer:

Past performance does not guarantee future results. Historical backtesting reveals how strategies performed in the past, but future market conditions may differ. Use SharkFintics as one tool among many in your retirement planning process.

Ready to test your retirement strategy?

Start with our free tier today and see how your plan would have performed through real market history.