For blockchain technology and cryptocurrency, 2021 is one of the most interesting years, both in terms of adoption and mainstream acceptance. From the government of El Salvador to large companies such as Tesla, Goldman Sachs, Bank of America and Morgan Stanley, many institutions have taken a step towards becoming part of the ecosystem.

Nevertheless, there are still some issues and incidents that have worsened the sentiment of cryptocurrency investors and the entire community.

U.S. SEC rejects VanEck's spot Bitcoin ETF
According to data from Cointelegraph Markets Pro, after the U.S. Securities and Exchange Commission (SEC) approved ProShares' Bitcoin Futures Exchange Traded Fund (ETF) in early October, Bitcoin rose to a record high of $68,789.63 on November 10. In terms of natural trading volume, the first-day trading volume of ProShares Bitcoin Strategy ETF (trading symbol BITO) is the largest of all ETFs ever, which shows how exciting the launch of the BTC ETF is.

Soon after, on November 12, the financial regulator rejected Van Eck's proposal for a Bitcoin spot ETF, which caused the price of Bitcoin to begin to spiral downward.

VanEck CEO Jan van Eck was very upset about being rejected.
We are disappointed by the latest news that the US SEC refused to approve our physical Bitcoin ETF today. We believe that investors should be able to obtain BTC exposure through regulated funds, and a non-futures ETF structure is a better approach.
--Jan van Eck (@JanvanEck3) November 12, 2021
Since Cameron Winklevoss and Tyler Winklevoss attempted to launch the "Winklevoss Bitcoin Trust" in July 2013, efforts to obtain US SEC approval for spot ETFs have been going on for more than eight years. Although so long has passed and the story about cryptocurrencies has changed, Gary Gensler's US SEC has not yet approved a Bitcoin spot ETF.

Eric Balchunas, a senior ETF analyst at Bloomberg, commented on the rejection of the US SEC. Regarding the US SEC's rejection of several spot ETF applications that have already been submitted, Balchunas has always bluntly expressed his dissatisfaction. He has become one of the well-known voices following the development of new ETFs surrounding cryptocurrencies such as Bitcoin and Ethereum.

Ethereum network: Gas fees are out of control
The Ethereum network has undergone a milestone upgrade in 2021: its London hard fork, through the Ethereum Improvement Proposal (EIP) 1559, put Ethereum into a deflationary track. As of the time of writing, 1.244 million ETH has been burned, worth more than $4.96 billion.

With the introduction of the destruction mechanism, in view of the increase in the use of decentralized finance (DeFi) protocols on the blockchain and the proliferation of Ethereum-based non-homogeneous tokens (NFT) in the crypto world, Ethereum's gas fees have also appeared Has soared sharply. Gas costs continue to exceed 100 gwei and will even continue until 2022. "Gwei" is the smallest unit of Ethereum, equal to 0.000000001 ETH.

On February 23, the gas cost of the network reached an annual high of 373.8 gwei. Although gas fees appeared to be under control from May to August, there have been several surges that have been very unfavorable to retail investors in the DeFi market since then. This has also led to several DeFi protocols and investors choosing alternative blockchain networks, such as BSC, Solana, Polygon, etc.

In order to solve this persistent problem, Ethereum co-founder Vitalik Buterin proposed to upgrade EIP 4448 and EIP 4490. This will be a temporary fix through a method called data sharding, which will reduce the zk-Rollup on the blockchain. cost.

However, it remains to be seen whether the proposal will pass the governance structure of the network, and the actual effect of these upgrades in reducing gas costs.

Solana network: outages and DDoS attacks
Solana was launched in April 2019 and has quickly grown into one of the leading blockchain networks, with a total lock-up value (TVL) of nearly US$12 billion. The price of SOL, the network's native token, has risen nearly 130 times, and the current price is about $180. The token hit an all-time high of $260.06 on November 7.

However, at 13:46 PM UTC on December 4th, Solana's network suffered an outage that lasted for nearly 6 hours. The mainnet cluster of the network stopped producing blocks at slot 53,180,900, which resulted in new transactions that could not be confirmed on the blockchain. The outage caused criticism from many traders and developers, who criticized the network on Twitter.

Scott Lewis, the co-founder of DeFi Pulse, was one of the critics. He cited Serum's order data as evidence of the lack of "real customer orders."

This is not the first time Solana has experienced downtime this year. As early as September, due to the distributed denial of service (DDoS) attack on Grape Protocol's first decentralized exchange issued on September 14th, the network suffered a 17-hour outage between September 14th and 15th. . A DDoS attack refers to a large number of coordinated devices or botnets that block the network through false traffic in an attempt to make the network offline.

Soon after the second downtime on December 4, the network suffered another DDoS attack on December 9, which caused the network to be temporarily blocked, but the network remained online during the entire attack.

Although the attack was blamed on Solana's basic design and historically proven use of consensus mechanisms, the developers still seem to be confident in the network's potential. Solana co-founder Raj Gokal elaborated on this DDoS attack on Twitter:

If you didn’t help the Solana community pay attention to these indicators, if you were lying or perpetuating a lie, if you competed for the crown and bouquet at the haters’ ball...
Keep your tweets until you are ready to do the hard work of expanding the cryptocurrency.
Before that, get out.

• Raj Gokalᵍᵐ (@rajgokal) December 12, 2021
  After the DDoS attack, Solana's on-chain development work has seen a significant surge in GitHub's daily submissions. In fact, the network surpassed Polkadot and Cardano from November 12 to December 13 and became the most developed blockchain network.

Binance Smart Chain Network: Security Vulnerabilities
Binance Smart Chain (BSC) is a parallel chain of Binance Chain. Both blockchains are designed and maintained by cryptocurrency exchange Binance. The BSC was first announced in April 2020 and launched in August 2020 shortly thereafter.

Since then, the network has developed into the second largest blockchain widely used to deploy decentralized applications​, second only to Ethereum. According to data from DefiLlama, the TVL in the DeFi protocol on the network is currently worth nearly $17 billion. On May 10, the peak of the previous bull market, BSC's TVL hit a record high of US$31.72 billion.

However, the network and the protocols running on it have been extremely vulnerable to security breaches since its introduction. Here is a list of DeFi protocols that have become victims of security breaches and hacking attacks:

PancakeBunny: Lightning loan vulnerability caused $200 million in losses

Spartan Protocol: Vulnerability caused $30 million in damages

Uranium Finance: $50 million stolen

Meerkat Finance: Rug pull caused $31 million in losses

pNetwork: Hackers attacked and lost $12.7 million in BTC

Bogged Finance: Flash loan vulnerability caused $3 million in losses

BurgerSwap: Lost $7.2 million due to security breach

Belt Finance: Lost $6.3 million

Considering that the above list is not exhaustive, it is safe to say that in the 18 months of operation of the network, hacking and security breaches that have occurred have caused hundreds of millions of dollars in losses. In addition to these security vulnerabilities, PancakeSwap decentralized exchange and Cream Finance have also been subjected to several phishing attacks.

However, the Binance ecosystem is trying to solve this problem in several ways. The latest effort is to introduce Project Shield, a security audit process that will add an extra layer of protection to users trying to gain exposure to BEP-20 and ERC-20 tokens on the Binance Exchange.

There are many things to look forward to
Although these events and problems caused the disappointment of the crypto community in 2021, it is clear that the growth of digital currency usage is higher than ever.

With the emergence of innovations such as NFT, GameFi and Metaverse, the cryptocurrency field is exploring the next big event in art, games, music, and finance through innovations that will change the status quo of the industry.