Many people had their first introduction to Bitcoin through "companies" like Gladiacoin... a program who promised 200% return on your Bitcoin in 90 days.
It was good because it got a lot of people into Bitcoin, but is turned out to be bad because they recently "closed shop" leaving many people losing a lot of money.
New Ponzi Schemes like this appear every day. Can you recognize them and steer clear to better investments, like legitimate Bitcoin/Crypto mining?
Great article detailing other companies that look dangerous: https://bitcoininvestment.news/gladiaco ... portfolio/