You should be EXTREMELY careful with any investments with Bitcoin. Anything that sounds too good to be true probably is. Never invest anything more than what you are willing to lose.
You should read up on Ponzis and HYIPs.
I started a thread about TopVestor here <
https://bitcointalk.org/index.php?topic=527771.0>. If you haven't signed up and want to, please use my referral link. I'm donating half my reward from referrals to Sean's Outpost!
I'm also in BTC Arbs. They seem legit (at least more so than most other Bitcoin investment sites).