https://killionlabs.com/updates/blog/ Retirement and portfolio research from Killion Labs: safe withdrawal rates, sequence risk, Monte Carlo, fees, and strategy. en-us Tue, 15 Sep 2026 23:24:33 GMT https://killionlabs.com/updates/blog/vanguard-dynamic-spending-vs-4-percent-rule/ https://killionlabs.com/updates/blog/vanguard-dynamic-spending-vs-4-percent-rule/ Sun, 30 Aug 2026 12:00:00 GMT Vanguard dynamic spending vs the 4% rule on 5,000 paired retirements: +$17,834 lifetime spending in the median world, -$198,351 in the worst tenth. Q1-Q4 run. hello@killionlabs.com (Berkay Kolay) retirement-withdrawals withdrawal-strategies flexible-spending backtesting https://killionlabs.com/updates/blog/monte-carlo-retirement-planning/ https://killionlabs.com/updates/blog/monte-carlo-retirement-planning/ Sat, 29 Aug 2026 12:00:00 GMT Monte Carlo retirement planning on one frozen retiree: real p50 $1.08M, p10 $0, p90 $5.69M at year 30, 10.4% ruin, versus a 7% deterministic path. 1,000 paths, seed 20260622. hello@killionlabs.com (Berkay Kolay) monte-carlo projections probability https://killionlabs.com/updates/blog/90-percent-success-not-100/ https://killionlabs.com/updates/blog/90-percent-success-not-100/ Fri, 28 Aug 2026 12:00:00 GMT 90% chance of success vs 100%: rigid 3.95% hits 90% on 1,000 paths. 2% still only 99.4%. 100% is not on the grid. hello@killionlabs.com (Berkay Kolay) monte-carlo probability retirement-withdrawals https://killionlabs.com/updates/blog/probability-of-success-vs-projected-balance/ https://killionlabs.com/updates/blog/probability-of-success-vs-projected-balance/ Fri, 28 Aug 2026 12:00:00 GMT Probability of success vs projected balance on 1,000 shared paths: 2% prints 99.4% and $1.89M median; 6% prints 63.0% and $308k. hello@killionlabs.com (Berkay Kolay) monte-carlo probability retirement-planning https://killionlabs.com/updates/blog/4-percent-rule-riskier-at-40-than-65/ https://killionlabs.com/updates/blog/4-percent-rule-riskier-at-40-than-65/ Fri, 28 Aug 2026 12:00:00 GMT 4% rule riskier at 40 than 65: rigid 4% success 78.7% over 50 years vs 93.5% over 25 years. 1,000 paths, seed 20260622. hello@killionlabs.com (Berkay Kolay) safe-withdrawal-rate 4-percent-rule early-retirement https://killionlabs.com/updates/blog/real-math-behind-coast-fire/ https://killionlabs.com/updates/blog/real-math-behind-coast-fire/ Fri, 28 Aug 2026 12:00:00 GMT Coast FIRE math: stop saving at 45 and 32.5% of 1,000 paths still hold $1.5M at 65, vs 56% if contributions continue. Seed 20260622. hello@killionlabs.com (Berkay Kolay) coast-fire fire savings-rate https://killionlabs.com/updates/blog/lump-sum-vs-dollar-cost-averaging/ https://killionlabs.com/updates/blog/lump-sum-vs-dollar-cost-averaging/ Fri, 28 Aug 2026 12:00:00 GMT Lump sum vs DCA: lump wins 56.3% of 1,000 paths and 62.9% of 97 independent 12-month tape windows. Pre-tax, not advice. hello@killionlabs.com (Berkay Kolay) dca lump-sum investing-behavior https://killionlabs.com/updates/blog/average-return-overstates-compound/ https://killionlabs.com/updates/blog/average-return-overstates-compound/ Fri, 28 Aug 2026 12:00:00 GMT Average return overstates compound: 5.01% arithmetic vs 3.27% geometric on 1,000 no-spend lives. $4.33M vs $2.62M median. hello@killionlabs.com (Berkay Kolay) compounding returns monte-carlo https://killionlabs.com/updates/blog/100-percent-stocks-quantified/ https://killionlabs.com/updates/blog/100-percent-stocks-quantified/ Fri, 28 Aug 2026 12:00:00 GMT 100% stocks quantified: 83.6% success and $1.11M median vs 60/40 at 93.9% and $945k. Rigid 4%, 1,000 paths. Not a historical claim. hello@killionlabs.com (Berkay Kolay) asset-allocation stocks retirement-risk https://killionlabs.com/updates/blog/how-many-monte-carlo-simulations-are-enough/ https://killionlabs.com/updates/blog/how-many-monte-carlo-simulations-are-enough/ Wed, 12 Aug 2026 12:00:00 GMT For most retirement plans, 1,000 simulations is enough: an 85% success rate lands within about 2 points, 83% to 87%. At 100 paths it is ±7. hello@killionlabs.com (Berkay Kolay) monte-carlo retirement-planning probability https://killionlabs.com/updates/blog/long-term-stock-market-leverage/ https://killionlabs.com/updates/blog/long-term-stock-market-leverage/ Tue, 18 Aug 2026 12:00:00 GMT Long-term stock market leverage: 201 multiples from 1.00× to 3.00× on the 1928–2025 tape. Median, left tail and the long path peak at different L. hello@killionlabs.com (Berkay Kolay) leverage leveraged-etf backtesting drawdown crash-survival https://killionlabs.com/updates/blog/withdrawal-rates-by-retirement-age/ https://killionlabs.com/updates/blog/withdrawal-rates-by-retirement-age/ Fri, 14 Aug 2026 12:00:00 GMT Safe withdrawal rates by retirement age: rigid 4% and Guyton-Klinger on 30- to 50-year horizons, 200 seeded paths, seed 20260814. CSV included. hello@killionlabs.com (Berkay Kolay) safe-withdrawal-rate 4-percent-rule retirement-withdrawals guardrails https://killionlabs.com/updates/blog/monte-carlo-vs-historical-backtesting/ https://killionlabs.com/updates/blog/monte-carlo-vs-historical-backtesting/ Thu, 13 Aug 2026 12:00:00 GMT Monte Carlo vs historical backtesting: overlapping 40-year tapes are not a probability. Simulation is assumptive and reproducible. Use both. hello@killionlabs.com (Berkay Kolay) monte-carlo backtesting retirement-planning https://killionlabs.com/updates/blog/does-monte-carlo-overstate-retirement-success/ https://killionlabs.com/updates/blog/does-monte-carlo-overstate-retirement-success/ Thu, 13 Aug 2026 12:00:00 GMT Does Monte Carlo overstate retirement success? Independent draws miss clustered crashes. Ignoring fees and floors will print a kind number. What we do instead. hello@killionlabs.com (Berkay Kolay) monte-carlo retirement-planning probability https://killionlabs.com/updates/blog/is-the-4-percent-rule-still-safe/ https://killionlabs.com/updates/blog/is-the-4-percent-rule-still-safe/ Wed, 24 Jun 2026 12:00:00 GMT Is the 4% rule still safe? Flexible 4% lasted in 100% of 5,000 simulations; rigid 4% failed 1.1%. Full safe withdrawal rate trade-off table. hello@killionlabs.com (Berkay Kolay) safe-withdrawal-rate 4-percent-rule retirement-withdrawals guardrails https://killionlabs.com/updates/blog/what-a-1-percent-fee-costs-over-40-years/ https://killionlabs.com/updates/blog/what-a-1-percent-fee-costs-over-40-years/ Wed, 24 Jun 2026 12:00:00 GMT What a 1% fee costs over 40 years: we simulated 5,000 lifetimes at 0%, 0.5%, and 1% expense-ratio drag. The dollar gap is larger than the percentage sounds. hello@killionlabs.com (Berkay Kolay) fee-drag expense-ratio investment-fees investing-costs https://killionlabs.com/updates/blog/market-crash-year-you-retire/ https://killionlabs.com/updates/blog/market-crash-year-you-retire/ Wed, 24 Jun 2026 12:00:00 GMT Sequence of returns risk explained: the same 40% crash dropped success from 86% to 71% at retirement age 65, but only to 81% at age 48. 5,000 simulations. hello@killionlabs.com (Berkay Kolay) sequence-of-returns-risk retirement-risk market-crash decumulation https://killionlabs.com/updates/blog/which-investing-strategy-wins/ https://killionlabs.com/updates/blog/which-investing-strategy-wins/ Tue, 23 Jun 2026 12:00:00 GMT Which investing strategy wins? We benchmarked buy & hold, rebalance, glide path, guardrails, optimizer, and panic selling across 5,000 identical market lifetimes. hello@killionlabs.com (Berkay Kolay) investing-strategy portfolio-benchmark guardrails rebalancing https://killionlabs.com/updates/blog/monte-carlo-simulation-personal-finance/ https://killionlabs.com/updates/blog/monte-carlo-simulation-personal-finance/ Mon, 22 Jun 2026 12:00:00 GMT Monte Carlo simulation in personal finance: a $4.3M projection landed at the 71st percentile; the median was $2.9M across 5,000 regime-aware lifetimes. hello@killionlabs.com (Berkay Kolay) monte-carlo financial-projections retirement-planning probability https://killionlabs.com/updates/blog/staying-invested-vs-timing-the-market/ https://killionlabs.com/updates/blog/staying-invested-vs-timing-the-market/ Mon, 22 Jun 2026 12:00:00 GMT Miss 10 best months: $744K becomes $264K on the same S&P 500 path since 1985. Why staying invested beats timing the market. hello@killionlabs.com (Berkay Kolay) market-timing stay-invested behavior-gap s-and-p-500