must have 10-20 calls from this # to my mobile.  I have never managed to answer - partly because the calls never last very long, partly 'cos I maybe driving (pull up , check the #, then want to ..... someone), or when I don'rt expect calls.

I have had the call ring then ring back again after 2 - 3 mins (extremely annoying if you have stopped the car twice.."

Several other reported incidents suggest it is from a Binary Options company called TradeRush - can't prove it  - never managed to answer the caller.

why are you calling me?

Yes it is from traderush. I've made the mistake to to register there and they started calling me with Unknown number and when they saw that I don't answer any more theyve called me 2 from this number:) it a nice work the trading option but they don't seem verry legit. If you want to make some money online you could try PTC from this link : http://legacyclix.com/?ref=iuliarobi

They call, I don't answer, they hang up and call back immediately. Left no voicemails.

I had the same thing happen. Called. Left no message. Then called back with in 5 minutes. Still no message.