There's a long standing belief that crypto dumps over the weekend, one reinforced by prices over the last few days. If systematic highs and lows do exist the market should adapt, causing the timing of the weekly dump to drift over time. Fortunately, it is easy to verify whether this belief holds true from historical price data. Hourly closing Bitcoin prices on Binance between August, 2017 and February 2020 are available from cryptodatadownload.com. Using this data, I calculated hourly prices in each week as the percentage of the weekly maximum. Afterwards, it is a simple matter to average all the weeks in a year, providing an indication of when Bitcoin is at its lowest.
As seen in the above figure, Bitcoin is generally at its lowest and highest during the weekend. Between 2017-2021, weekly lows moved from Sunday, to Friday, and back to Sunday. However, over the first months of 2021 the weekly dump has occurred Monday morning. Conversely, the best time to sell has drifted from Saturday to Sunday.
However, it could be argued that this data only demonstrates the average linear trend in Bitcoin prices over the week. In years where the price is steadily increasing, one should expect that the Saturday price will exceed that of the preceding Sunday. To correct for this bias, I detrended the price by fitting a 5th degree polynomial. As seen in the above figure, this was subtracted from the actual price, so that it now fluctuates around an average of $9900.
The same hourly prices over the week were calculated using this detrended data. As seen above, prices have still tended to pump on Saturday since 2017. However, this is usually preceded by a dump on Friday morning. More recently, Bitcoin prices have tended to dump Monday, rather than on the weekend. Therefore, the belief that crypto dumps over the weekend does not hold true every year.