5 ms·

You can also short on poloniex

• FabHK 9y ago
  But not BTC/USD, only BTC/USDT, opening another can of worms.
  • kindfellow92 9y ago
    You don’t need to short BTC/USD you just need to be able to short. You can always convert to USD after your arbitrage gains in BTC, which I do and have done.
    • FabHK 9y ago
      Suppose on exchange X, BTC/USD trades at 12000, on exchange Y, BTC/USDT at 10000. You sell an expensive BTC on X (for 12000 USD), you buy a cheap BTC on Y (for 10000 USDT). Now they nicely converge to 20000. You buy back a BTC on X, giving you a loss of 8000 USD. You sell a BTC on Y, giving you a nice 10000 USDT gain. So, you realised and locked in the projected 2000 USD arb profits - oh, assuming the 10000 USDT you got on Y can actually be exchanged for 10000 USD. You have exposure now to USDT/USD, and your arb profit (in USD) depends on that cross.
      • kindfellow92 9y ago
        No, you don’t arb on BTC/USDT. You arb on XXX/BTC and then convert BTC to USD regularly on GDAX.
        • FabHK 9y ago
          Got it. So we agree, the arb has to be on the same cross (XXX/BTC) on different exchanges.
          • kindfellow92 9y ago
            Yup. Bittrex is a good companion