比特幣強勢回歸漲逾 50%，市場再喊 10 萬美元目標價
全球最大加密貨幣比特幣（Bitcoin）正在捲土重來，已從近期低點大漲超過 50% 以上，紐約 10 日下午報 45,781 美元，強勁漲勢重振投資人的希望，即使前途不明朗也全力向前衝，開始憧憬比特幣上漲到 10 萬美元，奔向月球、飛往無垠太空。
關於大量負面新聞恐讓比特幣下探 2 萬美元的傳言，已經是過去式，現在市場的預測是比特幣可能大步向前再創新高，並且狂漲不歇，這是由於比特幣已連續四週上漲，月線可望連二紅，並創 2 月以來最強的漲勢，邁向改寫新高紀錄的途中。
加密貨幣基金公司 CoinShares 策略長 Meltem Demirors 表示，比特幣強勢回歸，儘管有新的監管審查制度，但許多投資人視為正面消息和催化劑，因為它消除很多困惑，或是一部分的不確定性，並認為加密貨幣將不再是金融界的一個神秘角落。
Meltem Demirors 指出，比特幣正對抗外界對其破壞環境的批評，價格不跌反升，儘管世界各地主管機構承諾要實施更嚴格的監管制度，像是中國採取措施打擊加密貨幣挖礦，但比特幣仍奮力向前。
美國決策者正以新的方式關注數位資產，美國證券交易委員會主席 Gary Gensler 上週形容，加密貨幣領域是「狂野西部」，可能會在交易稅上制訂規範，但政府在制定監管框架時，不會為了保護投資者而妥協。
市場暫時拋開憂慮，對這波飆漲提出目標價，其中彭博分析師提出，如果跟隨以太幣的漲幅，比特幣能飆到 10 萬美元，而 Fundstrat Global Advisors 的分析師 Tom Lee 也喊出比特幣到 2021 年底會到 10 萬美元的目標價。
（首圖來源：pixabay）
斷電、禁交易所，中國接連出招但比特幣似乎影響不大
儘管面臨中國政府多方圍剿，比特幣一度面臨重擊，但經過一個月，一切似乎和中國政府的盤算不盡相同。
為了讓中國數位人民幣業務順利開展，中國政府有計畫的一步步進攻比特幣，在多處政府連手斷電礦場後，比特幣全網算力腰斬，幣值也連續崩跌，許多人甚至就像中國政府期望的那樣，認為比特幣終究要走向泡沫化。
然而比特幣精巧的設計，反而讓中國政府無所施力。當比特幣價值增長，越來越多人覺得有利可圖而投入挖礦以獲取比特幣時，比特幣網路的挖礦難度也會隨之提升，迫使礦工必須要付出更多資源挖礦，這樣的機制有助於比特幣網路保持平衡。
相反地，當全網算力大幅下降，礦工大量退出時，比特幣的挖礦難度也會隨之下降，誘使更多人投入挖礦。在中國政府於 2021 年六月大舉斷電礦場後，比特幣全網算力腰斬，隨之而來的是難度迅速下降。
原先貢獻全網算力近 60% 的中國礦工退出後，比特幣挖礦難度在一週內下降了約 30%，簡單來說，雖然比特幣幣值因此下跌了 40%，但礦工要獲取比特幣所需付出的資源也下降了 30%。一來一往之間，中國政府斷電礦場的政策，反而是將原本由中國礦工壟斷的挖礦事業，拱手讓給海外礦工，而且消耗的電力還更少。
▲ 比特幣算力從谷底又慢慢回升。（ Source：Bitinfochart）
2021 年 5 月，比特幣全網算力來到歷史高峰 186MTH/s（每秒百萬雜湊值），在中國政府介入後，算力驟降至兩年來最低的 68MTH/s，然而經歷一個月，全球礦工們積極搶下中國讓出的機會，順勢搶購中國礦工便宜出售的礦機，目前算力已回升到 110MTH/s。
除了礦工，雖然中國政府明文禁止交易所，但中國用戶並未消失市場，幣安（Binance）與火幣（Huobi）依然提供中國用戶交易管道，想阻止這些去中心化交易所，光靠中國網路長城還不夠，恐怕還需要金融長城，禁止中國人民將人民幣兌換成他國法幣，才有可能禁絕交易所生存空間。
中國政府打壓無效，最有力的證據就是在過去一個月，這些與中國高度相關的亞洲交易所，包括幣安、火幣與 OKEx，依然是全球最活絡的加密貨幣交易所。相比之下，今年風光上市的美國交易所 Coinbase 交易量，都遠遠落後於這些中國政府認為不合法的交易所。
不可否認，中國政府對於挖礦和交易所的禁令，都對比特幣造成一定程度的衝擊，但短短不到兩個月，比特幣算力與幣值明顯恢復良好，超出許多人預期。過去兩週比特幣上漲超過 40%，幣值從跌破 3 萬美元到超過 4 萬美元，如今落在 38,994 美元，應該讓前陣子接手中國礦機的礦工樂不可支。
（首圖來源：Pixabay）
Here’s how much electricity it takes to mine Bitcoin and why people are worried
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Tesla CEO Elon Musk shook the crypto market when he said his company would no longer accept Bitcoin for vehicle purchases. His tweet on May 13 cites an increase in the use of coal and other fossil fuels to generate the power used for mining as the reason behind his decision. Bitcoin dropped by 14% after that tweet and it continued to fall.
Bitcoin, Ethereum, Dogecoin and other popular cryptos reached record highs this year, raising concerns about the amount of energy needed to mine the coins. Warehouses of Bitcoin mining rigs run 24 hours a day, consuming more power than the whole of Argentina. As the energy bill for crypto mining rises, so does the amount of carbon and waste, adding to the growing climate crisis.
To be clear, I strongly believe in crypto, but it can’t drive a massive increase in fossil fuel use, especially coal — Elon Musk (@elonmusk) May 13, 2021
Here’s what you need to know about crypto mining and its energy uses.
What is cryptocurrency mining?
When Bitcoins are traded, computers across the globe race to complete a computation that creates a 64-digit hexadecimal number, or hash, for that Bitcoin. This hash goes into a public ledger so anyone can confirm the transaction for that particular Bitcoin happened. The computer that solves the computation first gets a reward of 6.2 bitcoins, or about $225,000 at current prices.
Other cryptocurrencies use similar mining technologies, contributing to the overall energy usage.
What is a crypto mining rig?
It’s a barebones computer with multiple graphics cards, or GPUs, instead of the single-card standard. Rigs usually use powerful GPUs from Nvidia and AMD to handle calculations and require high-wattage power supplies. The popularity of mining has led to a shortage of graphics cards.
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Why is crypto mining so energy-intensive?
For starters, graphics cards on mining rigs work 24 hours a day. That takes up a lot more power than browsing the internet. A rig with three GPUs can consume 1,000 watts of power or more when it’s running, the equivalent of having a medium-size window AC unit turned on.
Crypto mining businesses can have hundreds or even thousands of rigs in one location. A mining center in Kazakhstan is equipped to run 50,000 mining rigs.
Not only do rigs take up power, they also generate heat. The more rigs you have, the hotter it gets. If you don’t want your rigs to melt, you need some cooling. Many mining rigs have multiple built-in computer fans. But if you have multiple rigs, the room quickly gets hot, requiring external cooling. Small operations, like those run by individuals, can get by with a typical standing fan. Mining centers, however, need a lot more cooling, which in turn requires even more electricity.
Now playing: Watch this: What is Bitcoin’s true environmental impact?
How much energy does mining take?
The Digiconomist’s Bitcoin Energy Consumption Index estimated that one Bitcoin transaction takes 1,544 kWh to complete, or the equivalent of approximately 53 days of power for the average US household.
To put that into money terms, the average cost per kWh in the US is 13 cents. That means a Bitcoin transaction would generate more than $200 in energy bills.
Bitcoin mining used more energy than Argentina, according to an analysis from Cambridge University in February. At 121.36 terawatt-hours, crypto mining would be in the top 30 of countries based on energy consumption.
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Why is taking up so much energy bad for the environment?
Fossil fuels account for more than 60% of the energy sources in the US. A majority of that percentage is natural gas and a minority is coal. The carbon dioxide produced by fossil fuels is released into the atmosphere, where it absorbs heat from the sun and causes the greenhouse effect.
As mining rigs consume more energy, nearby power plants must produce more electricity to compensate, which raises the likelihood that more fossil fuels will be used. States that have struggling coal power plants, such as Montana, New York and Kentucky, are trying to cash in by wooing crypto mining companies.
What’s being done about this energy problem?
Not much. The 3rd Global Cryptoasset Benchmarking Study from the University of Cambridge found that 70% of miners based their decision on what coin to mine on the daily reward amount. Energy consumption made up only 30% of their choice.
Access to renewable energy at a low price, however, attracts crypto miners. China’s Sichuan Province has the country’s second-largest number of miners due to its abundance of cheap hydroelectric power. Its rainy season helps to generate so much energy that cities are looking for blockchain firms to relocate in order to avoid wasting power.
Musk said in May he spoke with North American miners, and they committed to using renewable energy sources. He then tweeted on June 13 that Tesla would allow Bitcoin transactions again if there was “reasonable clean energy usage,” which he listed at being approximately 50%.
This is inaccurate. Tesla only sold ~10% of holdings to confirm BTC could be liquidated easily without moving market.
When there’s confirmation of reasonable (~50%) clean energy usage by miners with positive future trend, Tesla will resume allowing Bitcoin transactions. — Elon Musk (@elonmusk) June 13, 2021
The operators of Ethereum, the second-most-popular blockchain behind Bitcoin, are doing something to change the amount of energy its miners consume. Ethereum 2.0 is an upgrade that will be completed sometime this year or in 2022. Instead of computers trying to solve computations – referred to as proof of work – computers will be randomly selected to create blocks for the blockchain, while computers that weren’t selected will validate those blocks created.
To ensure miners do their job, each miner has to stake 32 Ethereum coins, also called Ether, which is equivalent to $85,000, hence the term for this protocol is called proof-of-stake. This change reduces the amount of energy needed for Ethereum mining.
What other cryptos are more energy-efficient than Bitcoin?
A growing number of coins – there are more than 10,000 of them – use the proof-of-stake protocol that Ethereum 2.0 will transition to, resulting in a drop in power consumption.
Cardano, for example, uses its own proof-of-stake protocol and consumes 6 gigawatt-hours annually. To put that in perspective, Cardano’s energy use is a GWh and a half shy of providing enough power for the South Pacific island country of Niue, with its population of 1,620 people, for a year. By comparison, Bitcoin uses 126.09 terawatt-hours annually, which is equivalent to the amount of energy Pakistan, with its population of 225 million, uses each year.
Following Musk’s May 13 tweet, Cardano reached record highs because it was seen as an environmentally friendly alternative to Bitcoin. Its price peaked at $2.47 on May 16, but its value fell and is currently at $1.57.