Buy and Hold vs Strategy Returns: The Baseline Every Backtest Must Beat

The buy and hold return is what you would have earned by buying at the start of a test window and doing nothing until the end. It is the honest baseline for judging any strategy, because it is the cheapest and simplest alternative that was genuinely available. And it is a hard bar to clear, because it trades almost never, stays invested through every recovery, and defers tax instead of paying it along the way.

Almost every backtest report prints a strategy return and a buy and hold return side by side. The number that carries the information is neither of them on its own. It is the gap between them, measured over the same window, on the same basis, after the same costs.

What the buy and hold figure measures

In words, the calculation is simple. Take the value of the holding at the end of the period, divide it by the value at the start, and subtract one. That gives the absolute return over the whole window. Annualise it, and you have the compound annual growth rate for the same period.

What matters far more than the arithmetic is which thing you are holding. Backtest reports use the phrase in two different senses, and they are not equivalent.

Buy and hold of the benchmark. You buy the index the strategy claims to improve on, hold it for the entire window, and reinvest dividends. This is the comparison that answers the question an investor actually cares about: was running the strategy better than owning the market it draws from?

Buy and hold of the strategy’s opening basket. You buy whatever the strategy selected on day one, then never rebalance or re-select. This is a different and narrower comparison. It isolates the value of the ongoing rules, the rebalancing and re-selection, from the value of the initial picks. It does not tell you whether either beat the market.

Two conventions decide whether the comparison is fair. The first is dividends. An index measured as a price index excludes dividend income, while a total return index assumes dividends are reinvested. Most strategies implicitly reinvest income, so comparing them to a price index hands the strategy a free advantage that compounds year after year. The second is costs. If the strategy return is gross of brokerage, securities transaction tax, stamp duty, GST and slippage, while buy and hold naturally incurs almost none of these, the comparison is not measuring skill. It is measuring the absence of an expense line.

How to read it

Read the gap, not the level. A strategy that compounded at a healthy rate during a period when the index compounded at a similar rate has demonstrated very little. A strategy that trailed the index in a strong market may have taken far less risk. The level tells you about the market. The gap tells you about the strategy.

Insist on identical windows and identical treatment. Same start date, same end date, same return frequency, same dividend convention, same cost assumptions, same handling of any cash that sat idle. If the strategy holds cash between signals and the benchmark is fully invested, that difference alone can explain the entire result in either direction.

Test the endpoints. Start-to-end returns are notoriously sensitive to the two dates chosen. Shift the start by six months and the ordering can flip. This is why rolling windows are more informative: they show whether the gap was persistent or the artifact of one lucky entry point. A gap that appears in most rolling periods is a different claim from one that appears only when the window begins at a market low.

Look at where the gap was earned. Plot the difference over time rather than reading a single figure. An excess return that arrived in one concentrated stretch and then flatlined for years is telling you the rules captured one specific episode. An excess return accumulated steadily is a different pattern. Neither is proof of anything, but they support very different descriptions.

Adjust for the risk taken. Beating buy and hold with twice the volatility and twice the drawdown is not the same achievement as beating it with less. This is why the comparison belongs next to risk-adjusted measures rather than standing alone.

Check that the baseline was actually investable. A buy and hold line computed on today’s index constituents is not a real alternative, because that list is built from companies that survived. The historically correct baseline uses the index as it stood on each past date, with the constituents that were actually in it.

What it does not tell you

It does not tell you whether the excess return came from skill or from exposure. A strategy that tilts toward smaller companies, or toward a single sector, or that simply runs more market sensitivity than the index, will beat a broad benchmark in the periods when that tilt is rewarded. The gap does not separate the tilt from the judgement. Attributing the difference requires benchmark-relative and factor-based analysis, not a two-line return comparison.

It does not tell you whether the result will repeat. A gap measured on history is a description of one path through one set of market regimes. Nothing in the arithmetic says anything about the next window.

It does not account for cashflows. Both figures assume a single lump sum invested at the start and left alone. Real portfolios take money in and pay money out, and the timing of those flows changes the realised return substantially. When flows exist, a cashflow-weighted measure is the correct tool, not a start-to-end return on either side.

It does not include tax unless you model it. Buy and hold defers capital gains until the position is finally sold, while a strategy that rebalances frequently realises gains as it goes. The difference in tax treatment is real money, and it is usually absent from a backtest.

It does not test capacity. The strategy return assumes every trade filled at the modelled price. As position sizes rise, or as the strategy reaches into less liquid names, the achievable price drifts away from the modelled one. Buy and hold of a large index barely notices this. An active strategy can be undone by it.

It does not describe the experience of holding either one. A comparison of end points says nothing about how deep the falls were, how long recovery took, or how many years of underperformance the strategy asked you to sit through before the gap appeared.

The value of the buy and hold column is that it is unglamorous and almost impossible to argue with. It is what the market gave to someone who did nothing. Any explanation of why a strategy is worth running has to start by clearing that line honestly, on the same window, after the same costs.

Related reading

• Portfolio metrics explained: the hub that maps every return, risk and cost metric to the question it answers.
• What is CAGR: how a start-to-end return becomes an annualised one, and what it smooths away.
• Rolling returns explained: why rolling windows are more honest than a single point-to-point comparison.
• Transaction costs in backtests: the brokerage, taxes and duties that sit between gross and net.
• Total return index vs price index: why the dividend convention decides whether a comparison is fair.

This article is educational. Altys Labs is not a registered research analyst or investment adviser, and nothing here is investment advice or a recommendation to buy, sell, or hold any security.