I have a rather theoretical question here, but maybe you can help me understand...

I am from Czech Republic, the currency, CZK is now capped against appreciation by central bank at exchange rate EUR/CZK 27, similar as Swiss franc used to be.

It is widely expected, the central bank will lift the floor in mid2017 and currency will appreciate.

The 6M forward exhange rate is EUR/CZK 26.8. Spot is 27.02. Interest rates are higher in CZK than in EUR.

Here is the idea: I borrow EURO at low interest rate, convert to CZK at 27, place at deposit interest rate in Czech and at the same time make a 6m forward contract to sell CZK at 26.8.

Here is what bugs me: I just made profit on the exchange rate. And as I did it via 6m forward, I had the profit locked from the beginning. So zero risk, but profit guaranteed.

That is weird. Is it really possible? Did I make some mistake in my thinking?

Btw in terms of interest rates: -0.23 euribor, Czech interbank deposit about 0.03. So I probably loose nothing in jnterest rate differential.

Thanks for your help.