Having data for the price of Bitcoin along the past 6 years we can compute, for example, the ROI (return on investment) of buying on May 4, 2014, by June 9, 2018. Or the ROI of buying on Nov 15, 2015, by Dec 3, 2017. This is exactly what’s shown in the next plot: The ROI of buying on any possible day, calculated at all of the possible days, and taking one sample every month.
Constructing the index funds
To do this, for each date I calculated how big each coin’s market cap is compared to the total market cap. That gives us a weight for each asset. With this, knowing also how much the price of each coin changed across time we can know the ROI of the fund.
Note that the weight of each coin in each fund is constant. Normally we want the weights of the assets in an index fund to change in time(so that the fund actually tracks the index). This is called rebalancing and I’ll explore it in the last post of this series.
Below there’s the same plot but calculating the ROIs of crypto index funds created with the top 500 coins in Coinmarketcap by February 2019. To create them
What was wrong with the first post?
In the previous post, I would look at the performance of investing in funds along several periods of time. Those periods started at different dates, all of them ended on the same date (~July 2018). It’s not wrong, but it’s like just looking at what’s highlighted in the right chart (color in the right plot would correspond to the height of the black (or green) markers in the left plot).
In this post, I’m looking at funds’ performance through periods starting at all of the possible dates, and ending at all of the possible dates from that (and not only ending at the latest date, like before). This approach tells us much more information.
These new charts are OK, but they don’t tell us much more than what we already knew: that the ROI of anything bought before the peaks of late 2013 and late 2017 was good after the price surges in those times; that anything bought after the 2013 peak was underwater for a couple of years… And it’s hard to compare them to each other, they look quite the same.
If we divide the ROI of index funds by the ROI of Bitcoin we get a much more interesting visualization, that tells us what would have been better, whether to just buy bitcoin or to buy a basket of coins weighted by market cap. Here it is, with weekly resolution:
This is much more interesting and tells us various things, some less obvious than others, about three main parts of the plot:
ROI before mid-2017 (yellow area at the left): before mid-2017, the ROI of investing in an index fund VS in Bitcoin would have been almost the same (because the weight of Bitcoin in such indexes would have been very high)
ROI after mid-2017, having invested before mid-2017 (green area, bottom right corner): The ROI of investing in an index fund before mid-2017 would have been almost 2x Bitcoin’s. This is because even though Bitcoin went up a lot in that time, the rest of the coins went up more.
ROI after mid-2017, having invested after mid-2017 (red area, top right corner): Almost all investments in crypto index funds that were made after mid-2017 have been worse than just buying Bitcoin. Interestingly, this is when most of the money entered the crypto space and when most funds were created. SFYL. Let’s zoom in
There was only a small window of green when the funds created between July 2017 and January 2018 did better than Bitcoin, but you can clearly see the exact moment around mid-2018 when this graceful animal ran out of sugar and Cardano couldn’t be pumped anymore.
In the 3rd (and last) post I’ll extend this analysis to explore if rebalancing the portfolios helps in crypto index funds and whether it would have been a good idea to put money in the Coinbase Bundle. I’ll tweet when it’s ready.