I got a call two weeks ago from someone who had bought around $30,000 worth of Bitcoin and then invested it entirely in GladiaCoin. He asked me to take a look to see what I thought.

When I visited the GladiaCoin site, I was horrified. It is very clearly a ponzi scheme. The pyramid structure appeals to a lot of people interested in multilevel marketing, so you can find a lot of multilevel marketing people on the internet promoting GladiaCoin.

My advice to the person that called me: Do not deposit anymore bitcoins there, and do not reinvest the payouts that you've already received. (A lot of people were reinvesting their payouts.)

The safest way to "make money" with your bitcoins is just to hold it, preferably in some form of offline storage. If you want to earn interest, you can loan it out to traders on exchanges (but if exchange ever gets hacked, you could lose your bitcoins). You can also try to trade on the market volatility by trading back and forth between Bitcoin and a well-established alt-coin (like Ethereum), but that is risky.