According to CFTC Feb 06 FCM report, Oanda is the biggest Forex broker in the USA.
http://www.cftc.gov/tm/tmfcm.htm?from=home&page=mktfcmcontent
http://www.cftc.gov/tm/tmfcm.htm?from=home&page=mktfcmcontent


Quote from ElectricSavant:
According to CFTC Feb 06 FCM report, Oanda is the biggest Forex broker in the USA.
http://www.cftc.gov/tm/tmfcm.htm?from=home&page=mktfcmcontent
Quote from Nana Trader:
Afaik featureless Oanda platform is no where close to IB TWS(except for having charts), i don't understand for what reason some retail traders still using Oanda, considering pip spreads being same today for both companies, with IB giving other extra benefits