I checked a little bit around and found that bitcoin-trade.biz considers itself as a so called HYIP. They are marketing bitcoin-trade.biz on multiple HYIP related sites and are heavily discussed on the well known ponzi forums.

The other day I was supposed to contact bitcoin-trader.biz to ask them about bitcoin-trade.biz. On the contact page at https://bitcoin-trader.biz/contact.php I've noticed some HYIP related statements, or lets rather say "Anti HYIP" related statements.

So I contated them anyway and received the following statement from Michael Brandenburg:

Hi, I have been using the site since mid December.

You do have to be careful where you put your coins.   The site has some . . . well, issues.   A .biz suffix for one, but also they work out of the UK (trading stops on UK holidays) but are incorporated in Panama with no locational address or phyiscal contact method.  

They also have glowing reviews from all over the world posted on their site after only a month of operation.  It feels like trying too hard.

That said, I did take a chance and invest some coins.  
I contacted them about my concerns (after I invested a few coins) and they were responsive and discussed things with me.
Their backend is pretty sophisticated and you can withdraw your earnings at any time without fees.  If it is a scam, it's had a lot of work put into it.  

They do post their results publicly and the returns were really good in December.
https://bitcoin-trader.biz/results.php
It opened up in November just before the price explosion, and the mining results that they posted for that month were much less dramatic.  I have a mix of trading and mining shares and I have made about 30% of my original investment back, and I've withdrawn about half of that and reinvested about half.
One very good thing I like about the site is that once you deposit bitcoin, your balance stays denominated in U.S. dollars AT THE RATE WHEN THE DEPOSIT WAS CREDITED, and your earnings are denominated in dollars so you are protected against price declines. (flip side is you don't benefit from price increases, but I think declines are more likely in the mid-term.)  When you want to withdraw, they convert your dollar withdrawal amount to bitcoin and send them to you, although they only process withdrawals once each day monday thru friday (I think it's 1600 GMT)

I'm treating it like any other investment and only putting in what I am willing to lose.  Personally, I recognize it could possibly be a long term scam, or even if its sincere could just fail as a business eventually, but I think it's good for a mid-term investment.
If you want to give it a try, here is my referral link.
https://bitcoin-trader.biz/?ref= [ref removed]

In fact, for anybody who signs up using my referral link, I'll buy you a trading share.  
Just post (or pm me, but it's easier to see who is 'first' if you post here) your username and user number after you sign up and once it shows up in my downline, I'll send you $20 worth of bitcoin. (They use the Mt. Gox rate) (Offer limited to the first 5 to sign up and buy a share)  

DISCLAIMER:
I am not associated with the site in any way.

Ciao a tutti innanzitutto! E'il primo post quindi, scusatemi se dovessi fare qualche errore o simile.
Io ho iniziato ad elaborare l'idea di entrare nel ambito Bitcoin proprio per il discorso dell'Arbitrage.
Personalmente mi sto documentando in inglese su alcuni modelli matematici che permettano di gestire l'arbitrage in tempi relativamente brevi.
Ho delle discrete basi finanziarie (il mio bkg è informatico) e la mia idea è quella di riuscire a creare un applicativo che sia in grado di operare in maniera autonoma su questo tipo di mercato basandosi proprio su questo argomento.
Io ho fatto alcuni conti e sembra che i modelli possano risultare indovinati.
Ora mi sto accumulando un piccolo gruzzoletto (da 0) per recuperare un entry-value interessante per iniziare a lavorarci su.

Vi tengo aggiornati in merito, naturalmente se qualcuno è interessato :-)
Ciao Paolo.

...hi i'm interested but there are rumors about Bitcoin-Trade to be an hyip (High-yield investment program)...
there is a bit of a need of trust... like... who are the people actually trading? linkedin profiles are available? list of transaction are available?

thanks

Si chiama "fare arbitraggio" se non ricordo male...
E' un po' un casino. Diciamo pure che 1)devi movimentare un certo quantitativo di denaro 2)devi masticare di finanza 3) devi avere anche c...

You may want to get some trust and reputation around hr e before creating a business such as this. I doubt many people are going to invest in a website posted by someone who just joined, has no posts, no WOT, and no trust...

See http://www.groupbitcoin.com/ for mining contracts.

I found something interesting

http://bitcoinscammers.com/xtrememiners-net

Definitely scam.
Their website seems to be down

Dear Customer,

We're glad that you consider buying products from Coreminer. I checked the link you provided and we are sad that we are on "possible scam" list. However I think this has to do with the fact that we have not shipped our first batch to customers yet, which means that our products have not been reviewed.

This is the reason why we provide 60 days refund guarantee for those who order products from us before December 31, 2013. We do this so that customers can feel safe buying from us.
Furthermore, for our customers to feel that they can trust us, we use legitimate services which handles all payments. All payments goes through Coinvoice or Bips.me, depending on the type of payment our customers choose.

I don't know exactly what evidence of good job means, but I can provide you with photos taken two days ago from our office of a running Oktari which shows that it has an average performance of 4000 Gh/s. I have attached those photos for you. You should be able to zoom in on the screen and tell that the avg. performance is just a bit over 4000 Gh/s.

If you want to order products from us, please fill the order form at our website.

Best Regards

Use a better translation service, because what you posted is meaningless.