$2,500 a month starts at 6% a year.
Can spending pressure and market trend work together in retirement?
Strategy in short: Each month, compare annual spending with the real portfolio and check whether SPY beat T-bills in at least 5 of the past 12 months. Use those two facts to choose among SPY, QQQ and T-bills.
Retirement answer: Spending-and-trend allocation supported more starting spending than Always SPY: 4.5% versus 3.8% a year funded 30 years in at least 95% of both sets of histories. These are historical thresholds, not recommended spending.
Return comparison: Both Spending-and-trend allocation and Always SPY ran out of money while paying this demanding withdrawal example.
$500,000 with $2,500 monthly withdrawals
Both paths paid the same inflation-adjusted spending. The chart shows how the rule changed the money left behind.
See how the two signals changed the portfolio
Low spending pressure keeps the strategy centered on SPY. Higher pressure adds QQQ. A weak SPY trend keeps either a T-bill cushion or a larger SPY share.
While paying withdrawals, risky exposure ranged from 0% to 100% as the rule responded to the portfolio.
Spending-and-trend allocation$0-100.0% deepest fall
Always SPY$0-100.0% deepest fall
April 2000 through June 2026. Distributions are reinvested. The calculation charges 0.10% of each risky asset bought or sold. Monthly spending starts at $2,500 and rises with inflation. Past results do not predict future results.
Did combining spending pressure with trend fund more retirements?
In this demanding $2,500-a-month illustration, both portfolios had run out by June 2012.
The retirement tests below answer the more useful question: how much starting spending lasted for 30 years in at least 95% of both sets of histories.
Example: You have $500,000 and need $2,500 a month—6% a year.
The portfolio had run out of money.
The portfolio had run out of money.
What funded at least 95% of both history tests?
Spending-and-trend allocation supported a 4.5% starting annual withdrawal for 30 years: 310 ordered starts and 4,791 of 5,000 mixed histories funded every withdrawal.
These are historical thresholds, not recommended spending amounts or a promise of future success.
Test if Spending-and-trend allocation can fund your early retirement with your own numbers
Enter your portfolio, monthly spending, and how long the money needs to last.
$2,500 a month for 30 years starts at 6.0% of the portfolio each year.
In these backtests, sometimes. Neither strategy funded this early retirement in at least 8 out of 10 histories tested.
315 starting months; the fund's record repeats in order when needed
- Spending-and-trend allocation
- 246 funded
- Always SPY
- 205 funded
5,000 histories built from 8–12-year pieces
- Spending-and-trend allocation
- 4,121 funded
- Always SPY
- 3,467 funded
A path funded the goal only if it paid every inflation-adjusted monthly withdrawal for 30 years. Results use the nearest 0.1 percentage-point starting withdrawal rate. They reuse one 26-year market record and are not a probability about your future.
How the FIRE calculator works
The calculator applies the portfolio value, monthly withdrawal, and number of years you enter. The first withdrawal occurs before the first month's return, and later withdrawals rise with U.S. inflation. A history counts as funded only if it pays every monthly withdrawal for the full period and finishes above zero.
One result begins at each of the 315 months in the fund record and follows that record forward in order, returning to its first month when more months are needed. The other builds 5,000 longer histories from linked 8-, 10-, and 12-year pieces of the same record. The calculation charges 0.10% whenever SPY, QQQ and T-bills is bought or sold and excludes personal tax.
At every repeated or rearranged join, market signals use the real observations that preceded the incoming historical month. Portfolio value, withdrawals, inflation and strategy state continue without resetting.
Strategy in detail
Each month, compare annual spending with the real portfolio and check whether SPY beat T-bills in at least 5 of the past 12 months. Use those two facts to choose among SPY, QQQ and T-bills.
The rule separates two risks: the plan can be strained because the portfolio is small, and markets can be weak at the same time. Its allocations respond differently to each combination.
Research has found that market direction can persist for months in many asset classes. See the 2012 time-series momentum study and a longer study across 67 markets. Those broad findings make the idea plausible; they do not validate this exact rule.
Can I trust these results?
My evidence-weighted estimate is about 47% that the main effect would persist in a new long market period. That makes the result uncertain, not dependable enough to treat as a promise.
The direct test covers April 2000 through June 2026. It includes fund distributions, T-bill returns, inflation and the stated trading costs, but it is still one U.S. market record. The longer retirement histories repeat it or link 8–12-year pieces; they test difficult orders, not new historical evidence.
Treat the result as evidence about how the rule behaved, then compare it with simpler alternatives and your own ability to follow it through a bad period.
Methodology details for the nerds
How I ran the return comparison
The test starts with the amount shown on the graph. Each decision uses only information already complete at that month-end. Distributions are reinvested, T-bills earn the published three-month rate, and the calculation charges 0.10% of each risky asset bought or sold.
How I tested retirement withdrawals
The first withdrawal occurs before the first month's return. Spending then rises with U.S. inflation. One panel checks every starting month in order; the other links 5,000 histories from 8-, 10-, and 12-year pieces. A path counts only if it pays every withdrawal and remains above zero.
Data and important limits
The calculation uses adjusted fund returns plus U.S. government T-bill and inflation data. Personal tax, spreads beyond the stated cost, and investor behavior are not included. A real fund can differ from its index because of fees and tracking.
Keep comparing
See where this strategy ranks.
Use this result
See how much you need to retire—and compare what to invest in.
Enter what you have and what you want to spend each month. Compare three portfolios against the same market history. Your financial figures stay in your browser.
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