I thought I posted this but appears that it didn't stick... Anyway, I'm a beginner with options and I use Reuters E**** for data and news. On the platform I can get option pricing from a number of sources. but some of the sources seem to have different RRs although vols are very similar... Let's take AUD/USD 3M 25D RR (see attachment) with a quote from ICAP at 4.9/5.9; Tullet Prebon bid -5.5; Citibank bid -5; Broker -6.15/-5.35 As you can see, three of the four show puts favoured over calls but oddly enough ICAP shows calls being favoured... I looked at charts for the broker and ICAP and the charts go back +1 year and the interesting thing I noted was that the broker showed RRs as always negative and ICAP the exact opposite. Now, maybe I'm missing something but I would just have to assume that during this time RR would have had to have been positive at some point for the broker and negative at some point for ICAP (see screenshot). Could someone explain to me which RRs to use ( I am thinking the negative ones i.e. broker) and why there is a discrepancy like this? Thanks in advance!!!