I'm currently interested in a derivative on $MRK (+0,22%) with a longer maturity. On Flatex, $MR1BZ7 comes up. Right now, that contract costs €0.68 there, and it matures on March 27. To keep costs down, I searched on TR for a comparable contract with the same maturity and strike price. There, the comparable SG contract costs 0.83, which is about 20% more. I think that’s pretty steep. I can’t even make up for that with the few euros I save on fees.
So if you want to buy classic options, always compare multiple issuers. Each of them calculates the premium and volatility differently.
