Dollar-cost averaging replaces the question of when to buy with a commitment to keep buying. Model a contribution schedule below, then see how much of the outcome comes from capital and how much comes from time.
Investment journeys
Every investment follows a different path
Dollar-cost averaging helps you stay resilient across bull, bear, and sideways markets by reducing dependence on market timing.
Recovery
Partial recovery
A deep decline is followed by an extended low period and only a partial recovery.
Stock price
Average purchase price
Both lines start together at $100. The price slides gradually, then falls sharply to about $29 by the middle periods and stays near that low for several years. Continued buying at those low prices pulls the average purchase price down to roughly $46, so the price only has to recover to $62 — still far below the $100 it started at — to finish well above the average cost.
The stock falls early, allowing more shares to be accumulated at lower prices before returning to its starting price.
Stock price
Average purchase price
Both lines start together at $100. The price falls 70 percent to a low of $30 by the middle periods, stays depressed long enough for several purchases to occur there, then recovers gradually to finish at exactly $100 — precisely where it began. Because contributions kept buying through the decline, the average purchase price ended near $57 rather than $100, so a flat price still leaves the position up roughly 74 percent.
The stock rises early, causing recurring purchases to acquire fewer shares before the price returns to its starting level.
Stock price
Average purchase price
Both lines start together at $100. The price climbs to a high of $164 in the early and middle periods, stays elevated long enough for several purchases to occur there, then declines gradually to finish at exactly $100 — precisely where it began. Because most contributions bought at elevated prices, the average purchase price ended near $124, above the final price, leaving the position down roughly 20 percent.
A dramatic early gain is followed by a significant decline, leaving these purchases at a loss even though the stock remains above its original price.
Stock price
Average purchase price
Both lines start together at $100. The price rises quickly and accelerates into a rally that peaks near $300, lingers close to that high, then declines significantly to finish around $182 — still well above the $100 it started at. Because a large share of the contributions were made during the rally and near the peak, the average purchase price climbed to roughly $193, above the final price, so this particular buying path ends below its average cost.
Higher ending price. Position still below average cost.
An early decline is followed by a strong recovery well above the starting price.
Stock price
Average purchase price
Both lines start together at $100. The price drops to about $38 by the middle periods, then recovers strongly and continues to $238 — far above where it began. The average purchase price settles near $78, because the early decline let contributions accumulate shares cheaply before the climb.
Long-term growth continues through several normal periods of volatility.
Stock price
Average purchase price
Both lines start together at $100. The price rises to $259 across the full period, interrupted by several pullbacks rather than climbing in a straight line. The average purchase price rises far more slowly, to about $150, so the gap between the two lines widens steadily through the later periods.
Higher ending price. Widening gap above average cost.
Frequent price movement creates activity without producing meaningful long-term progress.
Stock price
Average purchase price
Both lines start together at $100. The price then swings repeatedly between roughly $81 and $130, crossing above and below the average purchase price many times. After all that movement it finishes near $102, close to where it began, while the average purchase price settles near $105.
Solid line: projected value. Dashed line: capital contributed. The gap between them is compounding, not skill.
Why it fits a thesis-driven portfolio
Timing
Removes the entry question
A schedule decides when you buy, so you stop waiting for a better price that may never arrive. The decision you keep is which businesses deserve the capital.
Volatility
Turns drawdowns into accumulation
A fixed contribution buys more shares when prices fall and fewer when they rise. Declines become the mechanism rather than the emergency.
Conviction
Only works on a real thesis
Averaging into a company you cannot defend just automates a bad decision. Pair every schedule with written reasoning you are willing to revisit.
Projections are illustrative only. They assume a constant rate of return, which no market delivers, and they are not investment advice.
Illustrative barbell portfolio
Different paths. Deliberate position sizes.
Each line shows a holding's normalized return over time, while line thickness represents the monthly contribution. The diversified core carries the most weight, while higher-risk opportunities remain intentionally sized.
The chart stops at Aug 2026. Expanding it adds a single stress scenario, not a forecast, built from an assumed return for every holding in every year. Almost everything falls at once in 2030: the index core gives up 44% and the most speculative names close to 70%. Gold is the exception — it gains 38% in exactly the year the equities break, which is the entire argument for holding it. Position sizing is what decides how much a year like that costs you.
The grey line is cash: $1,500 a month into a money market at 3% a year. It never falls, and it is the line everything else has to beat to have been worth the risk.
Track record to Aug 2026
Return to Aug 2026
Illustrative portfolio example. Not investment advice or a representation of exact historical returns. The dotted Aug 2026–2035 section is a hypothetical scenario built from an assumed calendar-year return for each holding — not a prediction, and not a probable outcome. Sixteen of the seventeen equities fall together in 2030, by 11% to 68%; gold is assumed to rise. Read it for what 2030 does to the portfolio, not for where the lines finish: over nine years, compounding always favours whichever holdings were assigned the highest growth rates, which is the only reason the speculative sleeve ends above gold and the core. That ordering is an output of the assumptions, not evidence for them. Money-market returns assume a constant 3%, which real cash yields do not hold for a decade.
Portfolio Construction
Why the barbell?
A barbell strategy gives long-term investors both stability and meaningful upside: a dependable core of diversified or lower-volatility assets helps protect capital and preserve flexibility, while a focused group of higher-conviction investments creates room for substantial long-term growth. Thesis Pro is built for this balance. It filters routine market noise, tracks the assumptions behind your more aggressive holdings, and highlights when new information actually strengthens or weakens the investment case. The result is a portfolio designed to withstand uncertainty without giving up the opportunity to participate in transformative companies and industries.
Live market data
The same paths, in real markets
The trajectories above are illustrative. These are actual price histories, indexed to a common scale, so the dips and rallies a schedule would have bought into are the real ones.
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SPY chart by TradingView · Past performance does not indicate future results