Above is the line break chart of Bitcoin’s average daily computing power representing substantial fluctuations. For example, the hash rate 101.23 EH/s on September 16, 2019, dropped to 88.96 EH/s on September 17, 2019 — a decline of 12 percent. Increases or decreases of about 10 percent are very common. The reason for such a phenomenon is pretty explainable? As we mentioned above, the hash rate is the sum of all computing power. It does not necessarily mean that thousands of mining machines are switching on and off every day. In fact, the hash rate cannot be accurately counted. The data depicted by the chart above is not the actual computing power, but an estimate based on the difficulty and the time of block confirmation. Mining difficulty and computing power, together with luck, will affect this time. The luck of the whole network fluctuates greatly on a 24-hour scale, so the average daily computing power on a single day does not have much reference value. We must take a dimensional view of the computing power to reduce the deviation brought on by this luck. That is to say, the average seven-day computing power may have exceeded 100 EH/s, but the average daily computing power has not yet broken it.

For Bitcoin or all PoW-based cryptocurrencies, security does not depend on the hash rate but on the cost of 51 percent attacks. The higher the attack cost, the safer the network will be. The current increase in Bitcoin’s hash rate means that the requirements for 51 percent attacks on the network are correspondingly extended, but this does not mean that the cost of 51 percent attacks has grown as the unit cost of computing power should be taken into consideration.

Furthermore, there is no direct relationship between the Bitcoin hash rate and bitcoin’s price. Hash rate, by no means, determines the price. On the contrary, the price will more likely affect the hash rate. With the rise of the price, the miners’ profits are liable to grow, which consequently attracts more miners to join the network, thus increasing the cumulative hash rate.