Where does DMS get its data?
Every number on this site traces back to a small set of outside sources. There is no proprietary data feed and nothing is hand-entered. Knowing what feeds what makes it easier to judge how much weight any given figure deserves.
Monthly returns: Tiingo
The monthly return series behind every strategy comes from Tiingo's end-of-day data. This is the authoritative source. When a strategy's performance is computed, recomputed, or published, it is Tiingo's month-end closing prices doing the work.
Returns are total return, adjusted for dividends and distributions. This matters more than it sounds. For bond and commodity positions the income component is most of the return, and a price-only series would understate those assets badly rather than slightly.
Inflation: the Bureau of Labor Statistics, via FRED
The CPI series used by the Inflation Adjusted toggle is CPI-U, All Urban Consumers, not seasonally adjusted. It is pulled from the St. Louis Fed's FRED service, which redistributes the BLS figures. FRED also supplies several market indicators shown elsewhere on the site, including the high-yield credit spread.
The CPI is published with about a one-month lag, so the newest month usually has no official print yet. See the Inflation Adjusted FAQ for how that gap is handled.
Live quotes: Twelve Data and Yahoo Finance
Intraday numbers come from a different place than the historical record. The market strip above the navigation and the month-to-date figures during an open month are built from live quotes, refreshed through the trading day. Historical performance never depends on them.
This is a deliberate separation. Live quote feeds are fast and occasionally wrong. End-of-day data is slower and much more reliable. The site uses each for what it is good at, and nothing in a strategy's published track record is ever sourced from an intraday quote.
History before an ETF existed
Where a fund is younger than the track record shown, the earlier history is reconstructed from other sources. That reconstruction has its own rules and its own limitations, covered in full in the extended-returns FAQ.
What this means for the numbers you see
A few consequences worth carrying around:
- Monthly is the unit of account. Strategies are evaluated on month-end closes. Daily data exists for specific purposes, but a strategy's return, drawdown, and every statistic derived from them are monthly measurements.
- Dividends are already in there. You do not need to add a yield estimate on top of a published return. It is already counted.
- Nothing here is survivorship-screened after the fact. The ETF universe a strategy trades is fixed by its rules, not chosen in hindsight from funds that happened to do well.
- The data can be revised. Providers correct their own history occasionally. When they do, the corrected figures flow through on the next recompute, which can move an old number very slightly.
Where errors would come from
Being honest about the failure modes: the most likely source of a wrong number on this site is not the price data itself, which is well-tested and widely used. It is the reconstruction layer for pre-ETF history, and it is the transformation code that turns raw prices into strategy results. Both get audited, and both have had real defects found and fixed. The price feeds themselves have not been a meaningful source of trouble.