How the numbers on this site are produced, how often they change, and where they fall short.
Source
All fund data comes from TEFAS (Türkiye Elektronik Fon Alım Satım Platformu), the electronic fund trading platform operated under Takasbank, plus the public filings of the fund management companies. TEFAS has given written permission for the republication of this market data.
FonIndex is not affiliated with TEFAS, with Takasbank, or with any fund or management company.
Collection
An automated job queries TEFAS’s public endpoints each trading evening for prices and returns, and weekly for portfolio breakdowns and benchmark series. Requests are spaced at least 1.5 seconds apart so as not to burden a public service.
Updates are incremental — existing records are amended rather than the dataset being rebuilt — so a fund’s history stays stable between runs.
How figures are calculated
- Periodic returns (1M / 3M / 6M / 1Y / 3Y / 5Y): percentage change in unit price over the period. Cumulative, not annualised.
- YTD: cumulative change since 1 January.
- Annualised estimate: extrapolated from the average daily return over the last 30 days. It is an estimate, not a forecast, and short-dated funds are far more stable on this measure than equity funds.
- Deposit equivalent: a fund’s CAGR grossed up by the 10% withholding tax that applies to deposit interest but not to money market fund returns, so the two are comparable on a like-for-like basis.
- Category average: the mean one-year return across all funds in a category that report one.
- Fees: returns are derived from unit prices, which are already net of management fees. Fees shown separately are annual rates, published where TEFAS discloses them.
Currency
Every figure is in Turkish lira and is not converted. Lira returns should be read against lira inflation; each fund page shows performance against CPI inflation, gold, BIST 100, USD and EUR for that purpose.
Known limitations
Stating these openly is more useful than implying the dataset is complete:
- Price history depth varies. Collection does not cover every fund on every run, so most funds currently carry a few weeks of price history rather than a full year. Charts are labelled with the number of sessions actually held, never padded.
- Management fees are incomplete. TEFAS does not publish a fee for every fund. Where it is missing, the field is blank rather than estimated.
- Long-period returns depend on TEFAS. The 3Y and 5Y figures are taken from TEFAS directly, not recomputed here, and are absent for funds too young to have them.
- Category labels are translated. Fund categories are TEFAS’s own Turkish classifications rendered into English. Fund names are left in their registered Turkish form, because those are legal names and translating them would break any cross-reference against TEFAS or KAP.
Corrections
If a figure looks wrong, please write to ugur.sungur@gmail.com with the fund code. Corrections are made at the source of the problem rather than patched on the page.
Not advice
FonIndex publishes data and explanatory material. It does not provide investment advice, recommendations, or portfolio management, and it is not licensed to. Past returns are no guarantee of future results.