I wanted to know whether the market really always dips on Sundays and looked into the data. Spoiler: it does not.

tl;dr right at the beginning: people like to pretend that crypto always dips on Sundays and repeat that endlessly. I didn't believe it and did a very basic data analysis. Surprise: Sundays are not worse than other days in crypto, if anything they're a bit calmer.

If you've been on here for more than a week, you've probably seen people say it a few times: Sundays are almost always red, you should best wait for the "bloody Sunday" to buy the dip! That always bothered me a bit. My personal experiences don't align with that at all, Sunday doesn't seem different than any other day. And it wouldn't make any sense - if Sunday was the "dip day", wouldn't people catch on to that and be able to profit off that?

I was curious, so I did a very basic analysis of the data. Spoiler alert: "bloody Sundays" are not a thing. I looked at daily candles since 2017, which is somewhat arbitrary, but the starting date doesn't change the results much. I looked at data for BTC, but considering how connected all coins are, I don't think looking at other coins would be much different.

Starting out, which weekday has been "red" most often in the past 6 years? Thursday, followed by Monday and, in a tie, Tuesday and Sunday. However, the numbers are pretty similar for pretty much ever weekday, there have been between 149 (Friday) and 160 (Thursday) negative days since 2017 for every weekday except Saturday, which is a slight outlier and had less red days (134). If you look at how much, on average, BTC changed on each weekday, Thursday once again performs worst (+0.02%) and Monday performs best (+0.56%), with Sunday in between. What is slightly interesting is that on weekends, the changes in either direction tend to be a bit smaller than on weekdays, so it seems the markets are calmer on Saturdays and Sundays.

But maybe the biggest dips were on Sundays, right? So that's why so many people remember Sundays as being so red? Nope, not true either. The most negative days for BTC since 2017 were a Thursday, Tuesday, Thursday, Monday, Monday, Wednesday.... anyways, the first Sunday in the list ranks as the 22nd most negative day for BTC since 2017 with -11.06%, every single other weekday had at least one day worse than that.

Okay, I know many of you will now think "2017 is ancient history, but since I got into crypto, Sundays for sure have always been red" - unlikely! If I repeat the same "analysis" for a shorter timeframe, since the beginning of 2021, Sundays look even better. All days had almost the same amount of red and green days (it's been 110 weeks, and they all have between 54 and 56 red and green days, respectively) with Thursdays performing slightly worse (60 red days). Looking at average gains or losses, 3 weekdays are on average negative and 4 are positive - Wednesday, Monday, Saturday and, yes, Sunday. The average change ranges from Tuesday (-0.11%) to Wednesday (+0.30%). It is still true that changes in absolute values are a bit smaller on Saturdays and Sundays than on any other day of the week.

So, long story short, bloody Sundays are not a thing. Sundays are, on average, not red more often than any other day, the average change is not worse than on other days, and the worst dips and crashes in the past years exclusively happened on other days. Sundays tend to be comparatively quiet days in crypto. If your perception is different, it's probably because you read that bloody Sundays are a thing and now notice every time there is, indeed, a dip, but don't remember afterwards when Sundays are actually green.