BIST 100 is a market benchmark
BIST 100 tracks 100 selected shares on Borsa İstanbul under the exchange’s index rules. Constituents and weights can change over time. Its point level is neither a share price nor an average lira price of its companies. Investors access index exposure through products with their own terms rather than purchasing the index itself. Before comparing a product, identify its benchmark, currency and return variant.
Why many shares can fall while the index rises
Companies do not contribute equally to a weighted index. In a hypothetical three-share basket with weights of 50%, 30% and 20%, returns of +4%, −2% and −3% produce approximately +0.8% overall: 2 − 0.6 − 0.6. Two shares fall while the basket rises. This is not the actual BIST composition; it illustrates weighting. Read market breadth, sector distribution and the principal contributors alongside the index direction.
| Measure | Question answered | What remains outside |
|---|---|---|
| TRY price index | How did share prices change in lira? | Dividend reinvestment |
| Total-return index | How did performance include dividends? | Investor fees and taxes |
| Foreign-currency return | How did value change in another currency? | Personal FX execution and costs |
| Real return | How did purchasing power change? | Differences in individual consumption |
Price, dividends and currency
Price and total-return indexes treat cash dividends differently; the total-return version incorporates their effect. Comparing a dividend-inclusive portfolio only with a price index can mislead. Currency also changes the answer: a hypothetical 20% lira gain alongside a 25% rise in USD/TRY produces a gross dollar return of 1.20 ÷ 1.25 − 1 = −4%. Costs are excluded. Match dates and dividend treatment across both series.
A record level is not a purchasing-power measure
Exceeding a previous nominal peak does not by itself demonstrate a real gain. If a portfolio rises 30% while the relevant price index rises 25%, real return is 1.30 ÷ 1.25 − 1 = 4%. Subtracting gives a five-point approximation, not the exact compounded result. Official inflation may also differ from an individual’s spending basket. Keep dividends, currency, inflation and personal cash flows distinct when reading a long-term chart.
What else to check in an index-tracking product
Expenses, cash balances, execution timing and implementation can cause a tracking product to differ from its benchmark. Read the specified benchmark in the product documents instead of relying on the word “BIST” in its name. Check the weight date and remember that an index membership change is not a company valuation. Use contribution analysis to explain daily moves. An index is a useful reference, not a standalone measure of cheapness, safety or future return.
Related market pages and tools
Sources and further reading
Numerical examples are illustrative scenarios, not company data, bank offers or current tax rates.
This content is general information and financial education. It is not personalized investment advice or a recommendation to buy or sell.