Sounds great. Given that in stock market investing you are better off on average with passively managed tracker funds, there does seem to be a big gap in the market for a crypto asset equivalent. Having a crypto equivalent of an ETF as single tokens representing e.g. CMC100 would bring a whole host of challenges, e.g. regulatory, security, ease of manipulation (it is relatively easy for whales to temporarily get coins into the CMC100), etc. In the spirit of crypto, a solution you run yourself, and where you manage the keys to all the coins yourself, should go some way to addressing those concerns. Maybe in the longer term this sort of thing will be a smart contract you run yourself on a decentralised exchange to make it more easier.