90% of bitcoin’s supply has been mined and 4 other crypto updates you should know.

The price of bitcoin dropped at the start of the week after briefly rising above $50,000 on Sunday.

The largest cryptocurrency by market value is now trading at roughly $47,358 as of Monday afternoon, according to Coin Metrics.

Other big cryptocurrencies, such as ether, the second-largest cryptocurrency, are also down. The price of Ether is now about $3,813.

Along with price fluctuation, here are five significant developments in the cryptocurrency world over the past week.

1. Crypto executives testified before Congress

Executives from the cryptocurrency business testified before the House Financial Services Committee on Wednesday.

Rep. Maxine Waters, D-Calif., scheduled the hearing in an attempt to better understand crypto assets and explore future regulation.

"Digital assets trade in marketplaces that are fundamentally different from traditional financial markets because of their fledgling stage of development and unique underlying technology," Alesia Haas, Coinbase's chief financial officer, said in her testimony. "As a result, many existing regulatory systems are incompatible with this new technology."

After the hearing, Jeremy Allaire, chief executive officer of Circle, the issuer of the stablecoin USDC, said the discussion was positive rather than acrimonious.

2. Kickstarter said it’s moving to the blockchain

Kickstarter also revealed intentions to launch a decentralised version of its crowdfunding platform on Wednesday.

In a blog post, the firm stated, "We're supporting the development of an open source protocol that will essentially produce a decentralised version of Kickstarter's fundamental functionality." "This will be built upon, connected to, and used on a public blockchain by collaborators, independent contributors, and even Kickstarter competitors from around the world."

The new protocol does not yet have a name, but Kickstarter plans to move its site onto the protocol in 2022, Bloomberg reported.

3. Arrow Glacier upgrade to Ethereum went live

On Thursday, developers turned on Arrow Glacier, an update to the Ethereum network.

The so-called "difficulty bomb," which may potentially halt or stop Ethereum mining, has been moved back to June 2022 as a result of the upgrade. By then, Ethereum's developers intend to have switched from a proof-of-work to a proof-of-stake mining mechanism.

The "bomb" will be used by developers to encourage people to switch to proof-of-stake, because it will make proof-of-work mining much more difficult.

Developers had additional time to work on Ethereum 2.0, or Eth2, before the switch because the "bomb" was delayed.

4. ConstitutionDAO shut down in November, but its token just hit an all-time high

The Constitution DAO announced its closure in November after being outbid on a rare copy of the United States Constitution at a Sotheby's auction. However, the PEOPLE token, which is part of the DAO, continues to rise in value.

PEOPLE touched an all-time high of 17 cents on Sunday, according to Coin Gecko. In the last seven days, it has increased by more than 152%.

5. Bitcoin has been mined for 90% of its total supply 

90 percent of the total bitcoin supply of 21 million has been mined as of Monday morning, according to data from Blockchain.com. 

The rest won't be extracted until February 2140, at the earliest. Miners can continue to earn bitcoins till then.

Bitcoin has a proof-of-work architecture, which implies that miners compete to solve difficult math problems in order to validate transactions. It wasn't an easy road to 90 percent; it took 12 years to get there.