Please someone make available the general index of altcoins vs. BTC how it's been doing in the time of carnage. (over the course of a few weeks, and also since the dropping through the latest floor)
I would say 10-20 largest altcoins would be good for the index, but I also heard indices with established methodologies exist.
You mean something like this:
http://coinmarketcap.com/currencies/views/filter-non-mineable-and-premined/But with a long-term chart of the top items?
I mean a table where there's a certain startpoint (for example Sept 15, when the BTC latest fall started in earnest). Then it lists how the altcoins have done during the decline. There's some talk in XMR threads that it has performed poorly, but some also say that it is better than most. A factual comparison would be really good obviously!
I'm collaborating with a domain expert subscriber to this forum, working to develop something that would seem to broadly satisfy the requirement, the project's working title is "SandRaiser", btw.
I've been engaged in backfilling the data, it needs a bit more work but I should have something for you to look at later today (TZ=BST).
There are three indexes at the moment and a couple in speculative development :
1. FullMonty/+ - all altcoins with a calculable marketcap (very rough and ready, obv)
2. Key30/+ - top 30 coins by marketcap
3. NonMinables - an index of PoS-only coins.
1 & 2 are presented with and without LTC, hence the "/+" and have been balanced at August 23.
3 is balanced separately about a week ago (can't recall offhand).
The arithmetic is based on the equations laid out in
S&P maths tech PDF docIs this the kind of thing you had in mind?
Oh, I'll chuck this in, as well - add a few facts to the mix, I posted it a few days ago in a separate thread, it may well have escaped your notice:
Cheers
Graham
For what it's worth, Graham and I are working together on this project. I posted some preliminary stats about the index way upthread and made some weekly posts for a while, but as we got closer to something that could be displayed more easily, and as people stopped asking, I stopped posting.
We have elected to stick with cap-weighted indexes, as per the S&P (and most other popular indexes, with the exception of Dow Jones) methodology as opposed to a price-weighted approach. This appears to match Risto's approach. One thing to keep in mind, however, is that if one is using cap numbers, they are typically priced in fiat, most often USD. However, alts are most frequently priced in terms of BTC.
When BTC falls, even if the alt price (in BTC terms) held (for example, XMR at, say, .0035 BTC), the cap should fall. BUT this is somewhat offset by the fact that most alts have some kind of constant emission, so that it is possible for the price in BTC terms to decline AND for BTC to decline, but for the cap to actually increase in the face of all that.
In other words, it is not completely impossible that all or most of the reason that the alt caps did not decline as much as BTC could be related to emissions. My guess is that emissions are NOT enough to make up that substantial difference, though.
That said, it still seems as though using market caps is the most appropriate way of measuring. The emissions issue vs. priced-in-BTC seems to give a reasonable trade-off that might be as close as one can get to a true index-type value.
We are choosing our basket of alts (31 currently) using a combination of cap AND volume. BCN, for example, which makes Risto's list, is not in our basket due to low volume. We're working on a way to use 30 day volume to normalize the selection process just a little bit.
One other thing I would note is that we think our project is actually fairly important because it will allow a user to avoid sample size issues by choosing longer time periods in addition to the time period that they would like to see. Risto has chosen a fairly short period of time...less than 3 weeks. Alts have held up well in that time period. However, in the 8/14 through 8/18 time period, our basket of alts lost approximately 40% of their cap compared to BTC losing 30%. Why the divergence? With more data, we might be able to figure these things out.
Ultimately, we think the work is pretty important, in part, because there just are not accurate analyses out there. I think the question above is, basically, one about the beta of alts. In order to really figure out the answer, there has to be some longer-term data crunched. When that work is done, it will make a LOT more sense to contextualize this data over shorter periods, say, to analyze the impact of the BCX/XMR situation. To be sure, there have been periods where XMR outperformed the alt basket as a whole by a fairly wide margin.
There are some other indexes out there. Many of them include BTC, which makes it fairly useless for judging the beta of alts. Most of them show that alts, in fact, do have a much higher beta than BTC. As BTC has declined, alts seem to have declined a whole helluva lot more--looking over the course of several months. However, we felt like we could not be sure of their methodologies. We also felt like their user interfaces could use some improvements...for people looking to answer the very questions asked above!
In short, I'm not sure I'd take Risto's numbers as a guarantee that alts are more resilient than BTC...just that they have behaved that way for the last few weeks. That was decidedly not the case in August. Overall? Stay tuned!
