Not to worry: the index includes 1.5% DOGE, a meme coin, so you know it's a real investment vehicle.
But seriously- the purpose of an index is to mitigate risk by spreading your bets. Whereas all crypto rises and falls with Bitcoin, and Bitcoin rises and falls based on speculation, decoupled from any value it may or may not provide.
It's a financial instrument, not necessarily a good one. I wouldn't recommend holding this to anyone. BTC is the only 'low risk' investment. However, thinking about it, this would effectively work the opposite of an index as safe investment vehicle. Effectively it is pairing high risk assets - Altcoins - in the same bag as a "low risk" asset - Bitcoin. You are not trying to minimize loss, rather maximize gain at lower risk.
But seriously- the purpose of an index is to mitigate risk by spreading your bets. Whereas all crypto rises and falls with Bitcoin, and Bitcoin rises and falls based on speculation, decoupled from any value it may or may not provide.
So is this an index?