Comparison
Guardrails vs the bucket strategy
Guardrails change how much you spend. Buckets change where the money comes from. Here’s how each did on its own, and combined, through every market since 1928.
Historical success with $70,000 a year from $1,500,000: guardrails lasted in 67 of 69 starts; two buckets lasted in 60 of 69 starts; guardrail buckets lasted in 69 of 69 starts.
| Guardrails | Two buckets | Guardrail buckets | |
|---|---|---|---|
| Lasted 30 years (history) | 97% | 87% | 100% |
| Lasted (2,000 simulated markets) | 94% | 85% | 94% |
| Lowest yearly spending, starts that lasted | $56,000 | $70,000 | $56,000 |
| Typical total spending, whole retirement | $2.39M | $2.1M | $2.56M |
| Typical money left at the end | $1.52M | $2.69M | $2.27M |
| Years sold investments right after a drop | 8.1 on average | 2.5 on average | 2.7 on average |
Selling right after a stock decline locks in losses. The last row counts those years in a typical retirement.
- Guardrails
- Two buckets
- Guardrail buckets
What this means
With $70,000 a year from $1,500,000 (4.7%), guardrails lasted 30 years in 97% of historical starts and two buckets in 87%, against 100% for guardrail buckets.
Among starts that lasted, two buckets kept spending highest in its leanest year, never below $70,000. Two buckets had to sell investments right after a down year least often: about twice in a typical retirement, against about 8 times for guardrails.
No plan wins on every measure. Plans that adjust spending protect your savings but ask you to accept some lean years; fixed plans keep spending steady but need a lower starting rate to hold up in the worst markets. The right choice depends on how much flexibility your budget really has.
Two different problems
Guardrails
Solve “how much can I spend?” Spending adjusts to the market: small cuts after big drops, raises after strong years. Your investments stay in one mix.
Buckets
Solve “what do I sell?” A few years of withdrawals sit in cash and Treasuries. In a downturn you spend from cash and leave stocks alone. Spending itself doesn’t change.
Why combine them
Each covers the other’s weak spot. Buckets alone can run dry in a long slump, and then you’re selling low anyway. Guardrails alone still sell stocks every year, including right after a crash. Guardrail buckets use guardrails to set spending and the bucket to pay it, with one extra rule: in a lean year when cash is short, spend a little less rather than sell stocks.
The comparison above shows all three on the same savings. Look at the “sold investments right after a down year” row: that’s where buckets earn their keep.
Assumptions
- Fixed and guardrail plans hold 60% stocks and 40% 10-year Treasuries. Bucket plans keep 4 years of withdrawals in Treasuries and invest the rest 80% in stocks.
- Guardrails: cut spending 10% when the withdrawal rate rises 20% above its start, raise 10% when it falls 20% below, floor at 80% of starting spending.
- History tests every 30-year stretch since 1928. The simulated figure stitches together random 5-year blocks of real history (2,000 runs). No taxes or fees.
New to a term? See the retirement income glossary.
Common questions
Is the bucket strategy better than guardrails?
They do different jobs. Buckets reduce selling after down years; guardrails protect the plan’s long-run sustainability. Historically, combining them did best on most measures.
What is a guardrail bucket strategy?
A plan that uses guardrails to set each year’s spending and a cash bucket to pay it, refilling the bucket only when investments are near their high.
Related tools
How we calculate this
Each plan runs through the same historical stretches and the same simulated markets, so the only difference is the withdrawal rules. Bucket plans withdraw from cash and refill it only when investments are within 5% of their previous high.
Data: S&P 500 total returns, 10-year Treasury and 3-month Treasury bill returns as compiled by Aswath Damodaran (NYU Stern), and CPI-U inflation from the U.S. Bureau of Labor Statistics, 1928–2025 (2025 preliminary). Read the full methodology and limitations.