Here is the history for Bitcoin monthly returns since the year 2011.
For me, March is the worst, bloody March, if you look at the data, only 3 out of 11 March is the
positive return for Bitcoin.
I am much excited for this month which is April which became a correction month for bloody March in previous years.
It's nice when people are able to put even a bit of effort into their posts, as the OP clearly did not do when coming up with the premise for this thread. You however have posted something that is very interesting and is quite an eye opener. I guess the March just gone was rather an anomaly, however it is hard to extrapolate anything useful out of 10 years worth of data. The repeated actions of the 12 months over a period of 10 years could simply be random coincidence, it will be slightly more useful once we have 50 or even a hundred years worth of data to look back on. Quantum computing might make Bitcoin obsolete by that point, however it would be making most banking security systems in their current form obsolete too.