Guide to dollar-based investing
Short pieces explaining what a dollar-based price is, how it is calculated, and why it diverges from the lira price. Each one ends with a worked example using that day's real BIST 100 figures.
What does dollar-based mean?
Tracking a stock on a dollar basis means measuring its price in US dollars rather than Turkish lira. The same stock, on the same day, can tell two different stories depending on the unit you use.
How is a dollar-based stock price calculated?
The calculation is a single division, but getting it right depends on matching each close to the correct day's exchange rate.
Why look at the market in dollars?
A lira chart can be setting records while your purchasing power falls. The only purpose of looking in dollars is to separate those two things.
The difference between nominal and real return
Nominal return tells you how much the number of lira in your account grew. Real return tells you how much you can actually buy with it. The two can drift a long way apart.
Should you watch in dollars or in lira?
The right answer is to watch both, but depending on the question you are asking, one is more informative than the other.
How does the dollar rate affect the stock market?
The exchange rate affects the market through two separate channels: companies' real profitability, and the unit of measure itself. Confusing the two is the most common mistake.
Where is the BIST 100 in dollars since 2017?
In the years the lira chart printed record after record, the dollar BIST 100 was roughly where it finished 2017. That single comparison is what the rest of this site is for.
How does THY diverge from the index in dollars?
An airline earns a large share of its revenue in hard currency. The dollar chart shows whether THY actually separated from the BIST 100 underneath the lira records.
The example figures in these guides update automatically with the end-of-day close. Not investment advice.