No need to have an ICO, BitShares have the structure already coded to accommodate such index fund in the form of a smartcoin.
The market is open and the index is already tradable. BitShares Decentralised Exchange pair (BTWTY : BTS)

The work to build this index has been done on my team and my free time during these last 18 months without the need of investors.

You can't invest in the creation of this index fund but you can definitively invest in the index itself which has proved itself an amazing investment on the last 18 months. The price has almost triple !

https://s6.postimg.org/6rnygbarl/bit20_chart.png

Have a look on the other charts   www.bittwenty.com