For better understanding how Bitcoin Futures work on the Deribit platform, below is set out an example.
If you buy 100 future contracts with size US $10 each at a price of US $600 per BTC, you go long $1000 worth of bitcoin for $600 (100 contracts of US$10 dollar each makes US$1000). Imagine that you close the contracts by selling at $700. Basically you agreed upon buying $1000 worth of bitcoins for $600/bitcoin, and later you sold $1000 worth of bitcoin for $700/bitcoin. Your profit is 1000/600 – 1000/700 = 0,238095BTC or 166.66USD with bitcoin priced at $700. If both orders were taker orders, the total fee paid on this round trip would have been 2x 0.05% of 1000USD = 1USD (debited in BTC, so 0.5/600BTC + 0.5/700BTC = 0.0008333 + 0.00071425 = 0.00154755 BTC.) The margin you required to purchase US $1000 worth of contracts is $40 dollar (4% of $1000) and thus 40/600BTC= 0,0666BTC
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