I doubt Hedge Street are tax free for UK residents like IG Binaries are in the UK..
Therefore i wouldnt bother betting with them even if i could, the quoted prices and spreads seem to be identical to the other IG binary sites where IG are the only bidder/asker on Hedge Street.
Is the advantage of Hedge Street that you can buy/sell inside IGs spread? Dont know if thats worth the tax hit...