Completely erroneous these days in FX to say that the big stops are more often at '00' psychological levels. In the wholesale markets that's just plain wrong. They can be there, but usually only if the level signifies something else as well.
That said, what DOES tend to gravitate to round number levels is the choice of options strikes by end user customers. I say end user because they are more likely to go for plain vanilla buy and hold a certain strike type trading. An interbank / prop / hedge fund trader is more likely to trade somewhat differently (for a start they're usually trading vol) so the strike is often the last thing to be decided (i.e. they will trade 3m atms for example, or 1w 25d Riskies or whatever). Agree a vol price, try not to get their pantaloons pulled down on the forwards / depos / rounding or whatever, THEN solve for the strikes before booking it.
But a pension fund type might typically come in and ask for 3m eurusd 1.5000 calls say. THEN you have a nice round number and when you get to expiry the bank trader prob gonna be jobbing the gamma if we're near the strike.
Make sense?
GJ
