GLOBAL TRADER RANKINGS / RECORD COMPARISON
Sharpe Ratios: Sampling, Risk-Free Rates and Missing Paths
Why a standalone risk-adjusted number cannot establish a global trader ranking.
Identify the return series first
A Sharpe ratio depends on a series of excess returns, not a cumulative return alone. The calculation needs an observation frequency, a risk-free reference and a consistent return definition. A reported number without those records can be transcribed as an attributed claim, but cannot be independently reconstructed or used as a universal person-level score.
Daily account observations and monthly fund observations are not interchangeable simply because a report presents an annualised statistic. Cash-flow handling, costs and valuation practices can affect the series before any statistical formula is applied. Preserve these definitions before deciding whether two ratios answer the same question.
Annualisation is a modelling step
Scaling a periodic statistic to an annualised one can rely on assumptions about dependence and the return-generating process. Serially correlated observations or infrequently marked assets can complicate a simple square-root scaling. This chapter does not fit a statistical model to any real account and does not use a headline ratio to impute unseen returns.
For an editorial comparison, ask whether the report states the sampling frequency and the annualisation convention. If the original series is missing, leave the reconstruction field unresolved. A high ratio calculated under an unknown convention is not a substitute for the risk path needed to evaluate that account.
Choose and document the risk-free reference
The relevant risk-free input depends on currency, interval and the intended convention. A current quoted rate does not automatically reproduce a historical excess-return calculation. Keep the source and dated observations for the chosen reference, as well as whether the series was already expressed in excess returns.
If a source reports a ratio with no stated reference, do not assign a rate from memory and publish a newly precise estimate. A qualitative note can explain that the ratio's construction is unavailable. The missing input is a source limitation, not an allegation that the account's performance was poor.
Sample size and selection remain visible
A small observed sample can generate a strong ratio without establishing a stable long-run process. Looking only at surviving accounts or selecting the highest ratio from many variants adds further selection concerns. Count observations under the actual series definition and retain the historical population where a comparative conclusion is proposed.
No finite sample count alone certifies a future strategy. Software fixtures checking a formula are not independent financial observations. A ranking system should not combine a handful of polished backtests with a long realised series as though both supplied the same evidence. Keep simulated, reported and independently reconstructed statuses distinct.
Use a ratio as a bounded descriptor
A responsible profile can say that an identified report supplies a ratio for an identified account period. It should also state whether the series, expenses and reference rate were available for reproduction. Do not transfer a personal-account ratio into a current commercial product claim or use it to certify subscribers' execution.
This publication does not fill absent ratios or multiply them into an unsupported composite. The comparison dossier has separate provenance and risk fields precisely because a numerical summary cannot replace them. Readers should be able to see which conclusions survive even when the ratio is left unknown.
Original references and scope
Checked 14 October 2026. Citations support only their identified scope. Educational analysis and invented cases are this publication's own work, not empirical trader observations.
Apply the distinction
Use the complete authored packet to inspect how this issue changes the permissible comparison. Record unresolved inputs rather than replacing them with a made-up number. Keep an original source reference beside each factual observation, and state when the calculation is illustrative rather than based on an actual account.