Sundays are often the cheapest day to buy bitcoin. Trading volumes are typically lower than on any other day and low trading volumes often lead to lower prices. Sundays are quiet because the stock markets are closed and there is a natural drop in trading activity as people enjoy the weekend. As a result, there is often a natural drop in bitcoin prices. It is worth noting that the price advantages for buying on a Sunday may be quickly erased once markets reopen on a Monday. Therefore, finding the cheapest day to buy bitcoin may only be suitable for short-term traders.