Many people have heavily invested in bitconnect and the ROI is good too but there is 2 major points which just to get a BS alarm on my head.

Firstly even though Bitconnect token is worth over 100 USD it's not listed in any major exchanges.

Secondly the referral system is quite similar to a pyramid scheme.

There are many people who have invested and got their money back good for them but for one person getting there investment back three person doesn't get it.