Wow 21 bitcoin, that is enough for trading, i'll sign in this link
www.poloniex.com then if I get profit from trading i'll spend the profit to buy a car. And still 21 btc for trade.
Most of the links are fake, personally i don't believe on it. If we give our all amount only behalf of link, and if some days ago we never get the profit, so what we can do only the link, my mostly friend told me that online trading all are risky.
So, i avoid it, and better is that invest it. But now a days it is halving time, so save your bitcoins, to get the double profit.
I Agree with you, but poloniex is the most trusted site when it comes to bitcoin trading, neither its fake nor ponzi, I am successfully trading bitcoins on it since a long time and I don't have any complaint for the site.