What we are, however, is a better to invest in the stock market. The problem with investing in the stock market is (i) where do I invest? and (ii) when / how do I get out? The Instavest platform is a curated research base that's meant to show you the ideas that our out there. There is no obligation to invest (or follow, as you put it). You can poke around and if something strikes your fancy, jump in.
To come back to Index Funds for a second, I think that ~85% should be in Index funds unless you have an edge. The balance of your portfolio should be in higher returning assets. Its hard to do that buy yourself, however, and that's how Instavest adds value.
On the topic market efficiency, I think Warren Buffett said it best" "If I was running $1 million today, or $10 million for that matter, I’d be fully invested. Anyone who says that size does not hurt investment performance is selling. The highest rates of return I’ve ever achieved were in the 1950s. I killed the Dow. You ought to see the numbers. But I was investing peanuts then. It’s a huge structural advantage not to have a lot of money. I think I could make you 50% a year on $1 million. No, I know I could. I guarantee that.”
The reason why retail investors have a structural advantage is because they can invest small dollars in relatively inefficient parts of the capital structure. A large hedge fund or Goldman Sachs can't invest in a small cap company because that doesn't have high average daily trading volume because they have to put big dollars to work. This leaves a part of the market that is relatively uncovered with an opportunity to make substantial returns.
Folks on Instavest are not investing in Google or Apple, they are looking for overlooked stocks or opportunities to make incremental return like this (scroll to bottom of this link): http://blog.instavest.com/the-17-investment
Hope that clarifies things :)