Stakedwallet was a "staking wallet" that gave big profit rates.

Users were able to earn 2% a day as "passive income".

Why did it look good (enough to let people invest) ?

The profit rate was very big, so users wanted to deposit many in order to get more. Layout looked nice (like publish0x), so users thank that was professional.

They also used an interesting referral program, to let more "scamable people".

Weird things

They allowed users to stake bitcoin and litecoin (PoW coins), that is impossible with real staking.

They also gave very high interest rates (when it looks too good for being true, it isn't true).

They thanged their domain name (from stakedwallet.io to stakedwallet.biz).

When did the problems start ?

The problems started when rich users wanted to withdraw their coins. The interests were fake, so they didn't have it, and withdrawals took many time. They gave bonuses for users who locked their funds in stakedwallet, but users didn't stop withdrawing. At a moment, there was no fund and they exited.

Conclusion

Do not give your funds to the 1st "high interests" website, because (I won't say it enough) when it looks too good for being true, it isn't true.

There're many scammers and they've many strategies for scamming you.