You set the Quantity of an already existing position in the text field there.
BitMEX has other things in the pipeline too: including an interesting "swap" contract which is currently live on Testnet, which allows you to earn interest on bitcoin while you are holding a position. Stay tuned to hear what these guys have next.
Bitcoin futures position worth $4.9 Million margin called on OKCoin, trader loses $250,000-500,000
There was a monster selloff in bitcoin today, and the traders on OKCoin at 10x, 20x are feeling the volatility.
The drop was pretty steep. The market was trading at $490 on quarterlies while spot was about $468. The drop was all the way down to $455, a 7% fall and plenty to margin call traders who were anywhere from 10-20x leveraged long.
LocalBitcoins Database Allegedly Hacked, Usernames and Passwords for Sale Online
A hacker on Bitcointalk forum is claiming to be selling the full database of Localbitcoins usernames and passwords:
The contents are not verified, but the claim is building momentum as concerned OTC traders are starting to worry and change their password.
On Satoshibox he allegedly is selling the partial list for 0.05 BTC. It's unclear if there is a bigger list being sold. The full text of the post is below, links to any potentially illegal content removed:
Screenshot of the list at: http://i.imgur.com/CPbrJVa.jpg
Bitfinex has some new developments in the pipeline. They announced and have stated now in this Hangout that there are plans for:
Here you can see the 2-hour longBitfinex hangout video which interviews about their API and general exchange development topics: